Students flee through the sewers to avoid 'Tiananmen 2.0': Hong Kong protesters escape underground amid fears of massacre after Carrie Lam warned: 'Surrender is your only option'

Students under siege at a Hong Kong university are trying to escape through the sewers amid fears that police will storm the campus and open fire, causing a Tiananmen Square-style massacre.

Dozens of activists at Hong Kong Polytechnic University wrapped their knees and arms in plastic on Tuesday as they prepared to try and crawl to freedom through a perilous maze of underground tunnels.

There are thought to be between 100 and 200 students left on campus, locked into the third day of a violent standoff with police who are trying to get inside and break up the pro-democracy demonstration.

Around 600 people surrendered overnight Monday, 200 of whom were children who were questioned and released, alongside 400 adults who were arrested and now face 10 years in jail accused of rioting.

Speaking Tuesday morning, city chief executive Carrie Lam said the only option for the remaining demonstrators was to lay down their weapons, surrender and face the legal consequences.

While Hong Kong police chiefs refused to say Tuesday what their next steps will be, commanders have previously said they are willing to resort to using live ammunition if the situation becomes 'uncontrollable'.

That has led to fears of a repeat of the 1989 Tiananmen Square massacre, when peaceful pro-democracy student protesters were shot dead by the Chinese army.

+105

Dozens of students trapped on the Hong Kong Polytechnic University campus by a ring of police launched a desperate and risky escape attempt on Tuesday by crawling through the sewers

+105

Hong Kong leader Carrie Lam has urged the protesters to surrender on Tuesday, but faced with a possible 10-year jail sentence for rioting, many opted to try and escape instead  

+105

Students are also fearful of a Tiananmen Square-style massacre after police said they would be willing to use live ammunition if the situation spirals out of control

+105

Fearful of bloodshed and being arrested by police, many protesters staged increasingly desperate attempts to escape the campus, including lowering themselves into the sewer system

+105

An anti-government protester attempts to escape Hong Kong Polytechnic University by going through a sewer

+105

Student activists gather around an open manhole at the PolyU campus as they explore the sewer tunnels in an attempt to find a way off campus that will avoid both bloodshed and arrest

+105

A police officer brandishes a baton as a student, along with others who tried to evade capture at the PolyU campus, cower inside bushes close to a fence on Tuesday night

+105

Police detain protesters and students at PolyU after they were discovered tying to hide inside a hedge at the campus in the Hung Hom district

+105

Police escort a young man after he allegedly tried to escape from Hong Kong Polytechnic University on Tuesday night

+105

Police officers arrest student protesters forced to lie on their fronts at the PolyU campus in Hong Kong on Tuesday night

+105

+105

Police officers wearing heavy riot gear escort young men from the scene on Tuesday night after they attempted to escape a siege at Hong Kong Polytechnic University

Several dozen parents of the students are holding a vigil outside the campus, hoping to put pressure on the authorities to avoid bloodshed.

One mother in her 50s, whose surname is Chan and whose 18-year-old son remains on campus, said: 'I'm worried when the police go in to attack there will be heavy casualties, a Tiananmen 2.0.' 

Meanwhile on campus, protesters were removing metal manhole covers with some making exploratory forays into the fetid tunnels, following rumours of successful escapes from a campus ringed by baton-wielding police.

Pockets of protesters, some with thick bandages wrapped around their knees in anticipation of a long crawl to freedom, knot the holes discussing an unlikely - and highly dangerous - breakout.

AFP reporters saw one group on their stomachs practising crawling. Another group hugged each other in consolation after apparently agreeing not to take the route down into the unknown.

'The people outside can't help us,' a protester told local television as he prepared to descend into a sewer. 'So what can we do?'

One protester, gas mask on, and cling film wrapped around his arms, carried a torch as he descended with his backpack down the metal rungs into the subterranean gloom.

It comes after several dozen students escaped by clambering down ropes dangling from a bridge on campus on Monday night. The students abseiled on to the motorway below before being taken away on motorbikes.  

'The rioters... have to stop violence, give up the weapons and come out peacefully and take the instructions from the police,' Ms Lam said. 

Hong Kong police spokesman Kwok Ka-chuen says police have not yet decided their next steps to end a standoff at Polytechnic University but are still hoping for a peaceful resolution. 

Kwok said at a daily briefing Tuesday: 'We will be closely monitoring the situation, will continue to collect intelligence and decide the next step to take.'

Asked whether a deadline had been set for the anti-government protesters inside to surrender, Kwok gave no specifics. He also did not address reports that the authorities are planning to cut power and water to the campus ahead of a final clearance operation.

Kwok said more than 3,900 gasoline bombs were discovered on another campus, Chinese University, and he expected that large numbers of homemade weapons were also being stored at Polytechnic University. 

Some 235 injured were taken to hospital on Tuesday, the Hospital Authority said. 

+105

A police officer armed with a rifle is seen on the streets of Hong Kong Tuesday, hours after chiefs said they would be willing to use live ammunition on demonstrators

+105

State-owned Chinese media has also floated the idea of using snipers to take out student demonstrators, leading to fears there could be a massacre

+105

Fears of a Tiananmen Square-style massacre grew in Hong Kong on Tuesday as up to 200 students remained on the campus of the city's Polytechnic University, despite evacuations overnight (pictured, a man is taken for medical treatment)

+105

Hong Kong chief executive Carrie Lam said up to 600 people were evacuated overnight, 200 of them children who were questioned and released, and another 400 adults who were arrested

+105

Exhausted protesters sit wrapped in blankets after leaving the campus of Hong Kong PolyU, where up to 200 remain in a tense standoff with police

+105

Parents of students still trapped on the campus said they feared a 'Tiananmen 2.0' massacre after officers said they would consider using live ammunition against them

+105

Protesters, many of whom were suffering from hypothermia, wait to be treated by medics after leaving PolyU campus. They now face up to 10 years in jail accused of rioting

+105

Injured anti-government protesters are treated by medics at Hong Kong Polytechnic University overnight Monday

+105

Carrie Lam, whose resignation has become a key demand of the protesters, urged those remaining on the PolyU campus to put down their weapons and surrender, saying it is now their only option

+105

China also appointed a new Hong Kong police chief, Chris Tang Ping-keung (left), on Tuesday in a move sure to anger protesters who have been asking for greater autonomy from Beijing

+105

Unwell and injured protesters speak to loved ones on the phone as they wait for medics at Hong Kong Polytechnic University

+105

Protesters wait to receive medical attention after being evacuated from the PolyU campus overnight on Monday

+105

Hundreds of protesters arrived outside campus on Tuesday night and shone their phone lights at police as they prayed for the students trapped inside the university

+105

Protesters hold their illuminated phones in the air during an evening vigil for students who are still trapped on the PolyU campus after a three-day standoff with police

+105

A teacher takes part in protests over police treatment of students trapped inside a university campus in Hong Kong, faced with the prospect of arrest or a potential massacre

+105

Police say they have arrested around 1,100 people in the last 24 hours on charges including rioting and possession of offensive weapons (pictured, protesters holding a vigil near the Poly U campus)

+105

Protesters raise their mobile phones with lights on as they gather to show their support for protersters who are still inside the campus of the Hong Kong Polytechnic University

Police have made about 1,100 arrests in the past 24 hours on charges including rioting and possession of offensive weapons, they said. The total since citywide protests began in June is more than 5,000. 

Japan has confirmed that one of its citizens, believed to be a student who was visiting Hong Kong as a tourist, is among those arrested. 

Meanwhile Chinese foreign ministry spokesman Geng Shuang slapped down US Secretary of State Mike Pompeo after he gave his backing to the students, accusing America of double standards.

Geng said Tuesday that while the U.S. has 'appeared to be fair' concerning pro-democracy protests in Hong Kong, it harbors 'ulterior intention to intervene ... and double standards on violent crimes.'

Geng said efforts by Hong Kong police to enforce the law should not be compared to the violent behavior of 'extremist forces.'

The UN Human Rights office also expressed concern about the situation at the university, urging authorities to do all the can to deescalate.

A spokesman for the United Nations High Commissioner for Human Rights, Rupert Colville, said he is concerned about increasing violence by young people 'who are clearly very angry, with deep-seated grievances.'

Colville told reporters in Geneva that most protesters have been demonstrating peacefully, and that authorities had 'by and large' respected the right to freedom of assembly.

He urged Hong Kong authorities to 'address the humanitarian situation' of protesters at Polytechnic University whose situation was 'clearly deteriorating.'

Elsewhere on Tuesday, China appointed a new police chief in Hong Kong, a move sure to anger protesters who have been asked for greater autonomy from Beijing.

The new chief, Chris Tang Ping-keung, said rebutting fake accusations against police and reassuring the public about the force's mission would be among his priorities. 

He said following a ceremony Tuesday morning: 'We have to maintain the law and order in Hong Kong and there is a massive scale of breaking of law in Hong Kong and there is a certain sector of the community that also condones those illegal activities.'

Tang has been on the police force for more than 30 years and takes over from Lo Wai-chung, who is retiring after 35 years of service.

+105

An anti-government protester walks past a fire on a bridge at one of the entrance that leads into the Hong Kong Polytechnic University. Activists have used the blazes to keep police off the campus

+105

Firemen put out a burning car set on fire by protesters near Hong Kong Polytechnic University in an attempt to draw security services away from the campus and allow students to escape

+105

Firemen put out a burning car set on fire by protesters near Hong Kong Polytechnic University

+105

Protesters clash with police when they try to move to Hong Kong Polytechnic University to rescue other protesters surrounded by police

+105

Hong Kong's police spokesman said Tuesday that officers had not yet decided on the next step towards ending the campus stand-off, but said they were still hopeful of a peaceful conclusion

+105

Protesters from outside the university have gathered at the police cordon and were facing off against officers on Tuesday in the hopes of preventing further violence

+105

Police officers confront protesters during an anti-government protest in Hong Kong

+105

Family members of students barricaded inside Hong Kong Polytechnic University hold up signs during a protest

+105

Protesters leave from the main entrance to Hong Kong Polytechnic University campus as they surrender to police

+105

Protesters make their way around a makeshift barricade at Hong Kong Polytechnic University to surrender to police

+105

An injured youth sits under a space blanket at a casualty evacuation point near Hong Kong Polytechnic University

+105

People wearing face masks duck down as they walk at Hong Kong Polytechnic University in Hong Kong

+105

A young man carries an injured young woman to an ambulance as some protesters under the age of 18 leave from the Hong Kong Polytechnic University overnight Monday

+105

Ingredients used to make Molotov cocktails as well as a form of napalm that was used by students to keep the police at bay is seen inside Hong Kong Polytechnic University

+105

University authorities had previously said that students had stolen chemical stores and were using them to make weapons to be used against the authorities

+105

Police said they found almost 4,000 gas canister bombs at the site of another university protest, and expected to find more inside PolyU when the campus is finally cleared (pictured, ingredients for petrol bombs)

+105

A makeshift bow was among objects left behind by students in the canteen at PolyU after they surrendered following a three-day standoff with police

+105

A plastic skull is seen on top of a pole at the PolyU campus, where between 100 and 200 students are thought to be holed up

+105

A view of the gymnasium inside the Polytechnic University where some of the student protesters had been sleeping after a three-day stand off between activists and police

+105

Graffiti covers part of the badly damaged canteen inside Hong Kong's PolyU, which has been the site of major clashes between pro-democracy protesters and police

The Hong Kong government said Tang's appointment was made 'on the recommendation and nomination' of Chief Executive Carrie Lam, but with the final approval of the State Council, or Cabinet, in Beijing.

Also on Tuesday, a Hong Kong court rejected an appeal by pro-democracy protester Joshua Wong - who was arrested during the 2014 umbrella protest - to change his bail conditions so he can travel abroad.

Hong Kong's High Court denied Wong's application to leave the territory, citing the risk that he won't return.

Demosisto, a pro-democracy group that Wong founded, said he was invited to speak in several European countries including France, Italy and Germany. The court said Wong can give his talks through video recordings. 

Students have been taking part in pro-democracy protests at the university for almost a week, but scenes turned ugly overnight Sunday as riot officers tried to storm in and were met by volleys of napalm bombs and arrows as concourses were set alight to keep them out. 

Police were accused of using a 'sonic weapon' mounted on top of a truck to make activists sick and disoriented - which they denied - while pictures emerged of what appeared to be a gas canister bomb seized from students.

Hundreds of panicked and exhausted activists began trying to escape the campus on Monday morning, but were met by tear gas, rubber bullets and police batons. Many were arrested, and now face up to 10 years in jail for taking part in what Hong Kong's rulers have deemed a riot.