Hong Kong metro stays shut after night of violent protests

Hong Kong's metro system will stay shut on Saturday, the rail operator said, paralysing transport in the Asian financial hub after a night of chaos in which police shot a teenage boy and pro-democracy protesters torched businesses and metro stations.

Friday's protests across the Chinese-ruled city erupted hours after its embattled leader, Carrie Lam, invoked colonial-era emergency powers last used more than 50 years ago to ban face masks, which demonstrators use to conceal their identities.

Increasingly violent demonstrations that have roiled the city for four months began in opposition to a bill introduced in April that would have allowed extradition to mainland China but have since spiralled into a broader pro-democracy movement.

MTR Corp said its network, which carries about 5 million passengers each day, would remain suspended, while shopping malls and supermarkets also closed, in a new blow for retailers and restaurants in a city on the edge of recession.

"As we are no longer in a position to provide safe and reliable service to passengers in the circumstances, the corporation had no choice but to make the decision to suspend the service of its entire network," it said in a statement.

Protesters had set fires at stations, as well as to an empty train, and injured two staff, added MTR, which is known for operating one of the world's most efficient rail networks.

All stations closed late on Friday, stranding passengers and forcing many to walk home, a situation set to worsen as the city goes into a holiday weekend.

Further demonstrations are planned across Hong Kong through Monday, which is a public holiday, but it was not immediately clear how the transport shutdown would affect them.

More than a dozen shopping malls, supermarkets, and branches of Bank of China (Hong Kong), Bank of East Asia, and Industrial and Commercial Bank of China, which have been targeted by protesters, said they would not open on Saturday.

Lam, Hong Kong's Beijing-backed leader, said the ban on face masks that took effect from Saturday was ordered under emergency laws allowing authorities to "make any regulations whatsoever" in what they deem to be the public interest.

But the move enraged protesters, who took to the streets to vent their anger, many wearing masks in defiance of the ban. There were no immediate reports of arrests over the masks.

Demonstrators set fires, hurled petrol bombs at police and burned the Chinese national flag, in a direct challenge to authorities in Beijing.

Police said an officer in Yuen Long, a district in the outlying New Territories that saw fierce clashes in July, had fired a shot in self-defence after a protester threw a petrol bomb at him, setting him on fire.

Media said a 14-year-old boy had been shot and the city's Hospital Authority said his condition was now stable but gave no details.

About 100 demonstrators besieged a branch of the Bank of China (Hong Kong) in the high-end shopping district of Causeway Bay, while across the harbour in the district of Kowloon, protesters smashed the glass storefront of a China Life branch.

Police fired volleys of tear gas to disperse protesters in flashpoint districts such as Causeway Bay, Sha Tin and Wong Tai Sin, underscoring the challenges authorities face as the protests show no sign of letting up.

Hospital authorities said 31 people were hurt in Friday's protests, two of them seriously.