Hong Kong CNN  — 

Hong Kong’s leader invoked rarely-used emergency powers to ban people from wearing face masks during public assemblies, a move that enraged thousands of protesters who marched through streets across the territory on Friday night.

The city’s major transport network MTR suspended all of its operations after demonstrators vandalized a number of areas within Hong Kong – from train stations to shopping malls and banks.

The mask ban comes into effect on October 5, Chief Executive Carrie Lam announced at a press conference Friday, following a special meeting of her cabinet, the Executive Council.

The embattled leader said the order to enact the “Prohibition On Face Covering Regulation” was a “necessary decision” but insisted it does not mean Hong Kong was in a state of emergency.

“We are now in a rather extensive and serious public danger. It is essential for us to stop violence and restore calm to society as soon as possible,” she said. “We believe the new law will create a deterrent effect against masked protesters and rioters.”

Lam said she won’t set a date to nullify the anti-mask law.

The vast majority of people who have attended the city’s recent pro-democracy demonstrations do so wearing masks to hide their identity, fearful that they could be arrested or targeted by police. Gas masks and respirators to protect against tear gas, which is often used by authorities to disperse unauthorized gatherings, have also become commonplace.

In order to enact such a ban the Chief Executive Office will invoke the city’s colonial-era Emergency Regulations Ordinance, which grants the government sweeping emergency powers.