In response, police fired a fresh round of tear gas and pepper balls at the crowd.

The force said radicals had also hurled petrol bombs at the police station in Tsim Sha Tsui earlier, threatening the safety of staff inside.

Meanwhile, a government spokesman condemned protesters who had smashed traffic lights and blocked roads in the city. “The masked rioters seriously disrupted social order and citizens’ celebrations on Christmas. Their acts are outrageous,” he said.

Earlier, at 11pm in Mong Kok, black-clad radicals had smashed the glass walls of a HSBC branch on Nathan Road and started a fire at its entrance. Some protesters used umbrellas to shield those in the act.

Half as many midnight masses for Hong Kong Catholics on Christmas Eve

Outside Peninsula hotel in Tsim Sha Tsui, several rounds of tear gas were fired after 9pm near the junction of Nathan Road and Salisbury Road. Thousands had gathered there to disrupt traffic.

Riot police warned the crowd they were participating in an illegal assembly.

By 9.45pm, police again fired tear gas as radicals threw objects such as traffic cones onto the road outside the Space Museum. The stretch was closed off to traffic.

Scores of black-clad protesters then formed a cluster and opened their umbrellas on Salisbury Road in a stand-off with officers. A water cannon sprayed jets laced with pepper solution to disperse crowds.

At nearby Mira hotel, volleys of tear gas were fired, with many people fleeing. A sponge grenade was also later found on Kimberley Road.

In Mong Kok, where thousands of protesters packed the junction of Argyle Street and Nathan Road, some radicals started a fire at exit C of the MTR station, while others climbed onto its roof.

In a statement at 10.50pm, the MTR Corporation said Mong Kok station was closed and all trains would skip the stop. Five minutes later, the rail giant also announced that Tsim Sha Tsui station would close.

Subway services citywide are running overnight, as is the usual practice on Christmas Eve.

Earlier still, trouble had broken out at Harbour City shopping centre in Tsim Sha Tsui as protesters there attacked people they suspected of being undercover officers. When some protesters threw objects at officers who had entered the mall, police pointed their crowd-control weapons at the demonstrators.

By 9.30pm, riot police were still stationed at the mall, with more than 50 people, mostly masked, heckling them.

“Where is your conscience?” they asked officers. “Where were you on July 21?” others yelled, referring to the Yuen Long attacks in which police were accused of arriving late to the scene, where white-clad thugs had beaten commuters indiscriminately.

Jason Ng, 51, who was at the mall and wearing a mask, said the force should be blamed for the social unrest. “Police should get better training,” he said. “People are just coming out to express their feelings. It’s police who turn these into physical conflicts.”

Mall management later asked people to leave through an announcement citing an “urgent situation”.

In Sha Tin, shortly after 7pm at New Town Plaza, where intense clashes between protesters and police previously erupted, about 200 people, some masked, started shouting protest slogans in the atrium area which connects to the MTR station.

An 18-year-old student, who only gave her surname as Chan, said she decided to join the gathering to stand up to what she called police violence and keep the anti-government movement alive.

At Yoho Mall in Yuen Long, another flashpoint for violent clashes, protesters had also gathered for the evening. Police said a man was arrested at around 8pm, after he fled following a request to be stopped and searched.

He was subsequently apprehended, but during the chase, the suspect jumped over a barrier and fell to the first floor of the mall. He was sent conscious to the hospital for treatment.

A medical source later said the man was in a stable condition.

On the other side of the harbour at 8pm, more than 100 masked individuals, some in black, gathered in Times Square in Causeway Bay. They chanted: “Five demands, not one less,” together with a growing crowd. Some also waved flags bearing the popular slogan “Liberate Hong Kong; revolution of our times”.

Earlier, as night fell, Commissioner of Police Chris Tang Ping-keung visited officers patrolling the streets of Tsim Sha Tsui.

Flanked by a group of riot police and other officers, Tang urged radical protesters to refrain from disrupting public order.

“Black-clad rioters should not come out and bring destruction – let Hong Kong have a peaceful Christmas,” he said after touring Canton Road, Peking Road and Nathan Road.

Citing a recent survey but not naming the source, Tang expressed concern over its results indicating 40 per cent of respondents support the protest violence.

“We are concerned and worried about this view,” he said.

Separately, Chief Executive Carrie Lam Cheng Yuet-ngor expressed her wish for a safe Christmas for Hong Kong people.

“Christmas is a day of joy,” Lam said in a 10-second pre-recorded video on social media. “I wish Hongkongers a peaceful, safe and merry Christmas.”

Hong Kong has been roiled by more than six months of anti-government protests, sparked by the now-withdrawn extradition bill.

Additional reporting by Sum Lok-kei