At least 22 anti-coup protesters were killed in the industrial Hlaingthaya suburb of Myanmar’s main city on Sunday after Chinese-financed factories were set ablaze, said an advocacy group.

A media report quoted the Assistance Association for Political Prisoners (AAPP) as saying that 16 protesters were killed in other places, making it the bloodiest day since the military coup imposed on February 1.

Many Chinese staff were injured and trapped in arson attacks by unidentified assailants on garment factories in Hlaingthaya, the Chinese embassy said.

The Chinese embassy has called on Myanmar to protect Chinese property and citizens.

China is reportedly in support of the military junta that has taken power.

According to local media, as plumes of smoke rose from the industrial area, security forces opened fire on protesters in the suburb that is home to migrants from across the country.

“It was horrible. People were shot before my eyes. It will never leave my memory,” the report quoted a photojournalist on the scene as saying.

Martial law was imposed in Hlaingthaya and another district of Yangon, the commercial hub and former capital of Myanmar, state media said.

Myawadday television run by Army said security forces acted after four garment factories and a fertilizer plant were set ablaze and about 2,000 people had stopped fire engines from reaching them.