An eery calm hung over Hong Kong on Saturday after businesses and metro stations were torched during a violent Friday night protest against a government ban on pro-democracy protesters wearing face masks.

The city’s entire mass transit rail system, which normally carries 5 million passengers a day, was suspended on safety grounds, while shopping malls and high street stores remained empty and shuttered.

The global financial hub remained peaceful but uneasy on the first day of a ban enacted by Carrie Lam, the Chief Executive, using the Emergency Regulations Ordinance – a sweeping colonial-era law that allows the government to bypass the legislature during a time of public danger.

Ms Lam introduced the unpopular measure on Friday in a bid to quell four months of anti-government protests, but tens of thousands immediately poured onto the streets in opposition. Demonstrations that spiraled into violent clashes and the shooting of a teenager by a plain clothes police officer under attack.

In anticipation of more unrest, supermarkets closed their doors early on Saturday as residents rushed to stock up on dried and canned foods, emptying shelves. Early closures by the 7/11 convenience store chain, known to stay open during typhoons, was greeted by widespread surprise.