Hong Kong’s government may censor the internet in a bid to contain months of increasingly violent pro-democracy protests, a cabinet member said Monday, after an emergency-law ban on demonstrators wearing face masks failed to quell the unrest.

The warning came as the international financial hub remained partly paralysed from three days of protests in which the city’s rail network and business outlets seen as pro-China were badly vandalised.

The surge in protests was in response to the Hong Kong government’s announcement on Friday it would invoke colonial-era emergency laws not used for more than 50 years to ban demonstrators from wearing face masks.

Chief executive Carrie Lam said the ban was needed to contain the unrest, which began nearly four months ago and seen millions of people take to the streets demanding China stop strangling their freedoms.

In a radio interview on Monday, Ip Kwok-him, a veteran pro-Beijing politician and member of Hong Kong’s executive council, fuelled those concerns when he said controls on the Internet could be introduced.

“At this stage, the government will consider all legal means to stop the riots,” Ip told Commercial Radio.

“We would not rule out a ban on the internet.” The Internet has been crucial to protesters, who have no public leaders and use online forums and encrypted messaging apps to mobilise.

The executive council is Hong Kong’s cabinet, an advisory body to Lam.

She announced the ban on face masks after meeting with the council on Friday.