Hong Kong’s Metro system stayed shut on Saturday, paralysing transport in the Asian financial hub, and malls and shops closed early after a night of chaos in which police shot a teenage boy and 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 for the first time in more than 50 years to ban the face masks demonstrators use to hide their identities.

The night’s “extreme violence” justified the use of the emergency law, Beijing-backed Lam said in a television address on Saturday.

“The radical behaviour of rioters took Hong Kong through a very dark night, leaving society today half-paralysed,” she said in pre-recorded remarks.

“The extreme violence clearly illustrated that Hong Kong’s public safety is widely endangered. That’s the concrete reason that we had to invoke emergency law yesterday to introduce the anti-mask law.”

But undeterred by the ban and transport shutdown, several hundred pro-democracy protesters, many wearing masks, took to the streets on Saturday, marching through the normally bustling central district of Causeway Bay.

Other groups gathered in Sheung Shui and Tsim Sha Tsui districts as the sun began to set.

“We’re not sure what is going to happen later, but we felt we had to get out and show our basic right to wear a mask,” said one protester, Sue, 22, who wore a black mask and dark glasses to the Causeway Bay march. “The government needs to learn it can’t squeeze Hong Kong people like this.”

China’s Hong Kong and Macao Affairs Office said on Friday the protests were evolving into a revolution backed by foreign forces and could not continue indefinitely.

The United Nations human rights chief called on Saturday for an independent probe into the violence during anti-government protests in Hong Kong, saying the injuries were alarming.

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 (Metro) 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. Reuters