Thousands have joined unplanned protests in Hong Kong after the territory’s government announced a face mask ban, which came into effect at midnight (16:00 GMT).
Chief executive Carrie Lam invoked a colonial-era emergency law in a bid to quell months of anti-government unrest.
The ban comes after an escalation of violence during protests on 1 October, when an officer shot a demonstrator.
Protesters immediately took to the streets after the ban was announced.
Many left work early to join the spontaneous demonstrations. Some furious protesters blocked roads, torched Chinese flags and vandalised stations and businesses, as police fired rounds of tear gas.
The territory’s Mass Transit Railway (MTR) announced a full service suspension of all trains. A spokesman told the BBC this was due to vandalism and attacks on staff.