Hong Kong’s embattled leader Carrie Lam invoked colonial-era emergency powers on Friday for the first time in more than 50 years in a dramatic move intended to quell escalating violence in the Chinese-ruled city.

Lam, speaking at a news conference, said a ban on face masks would take effect on Saturday under the emergency laws that allow authorities to “make any regulations whatsoever” in whatever they deem to be in the public interest.

Many protesters wear masks to hide their identity due to fears employers could face pressure to take action against them.

“Almost all protesters wear masks, with the intention of hiding their identity. That’s why they have become more unbridled,” said Lam.

“We can’t keep the existing regulations idle and let violence escalate and the situation continue to deteriorate.”

Lam described the territory as being in serious danger, but not in a state of emergency.