Myanmar activists planned more anti-coup rallies on Monday, a day after at least 39 people were killed in clashes with security forces in Yangon where Chinese-financed factories were torched.
Security forces killed at least 22 pro-democracy protesters in the Hlaingthaya suburb of Yangon on Sunday, an advocacy group said.
A further 16 protesters were killed in other places, the Assistance Association for Political Prisoners (AAPP) said, as well as one policeman, making it the bloodiest day since the February 1 coup against elected leader Aung San Suu Kyi.
Martial law was imposed in Hlaingthaya and in the Shwepyitha districts of Yangon, state media announced. The Chinese embassy said many Chinese staff were injured and trapped in arson attacks by unidentified assailants on garment factories in Hlaingthaya, and that it had called on Myanmar to protect Chinese property and citizens. China is viewed as being supportive of the military junta that has taken power.
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 Myanmar, media and witnesses said.
"It was horrible. People were shot before my eyes. It will never leave my memory," said one photojournalist on the scene who did not want to be named.
Army-run Myawadday television said security forces acted after four garment factories and a fertiliser plant were set ablaze and about 2,000 people had stopped fire engines from reaching them.
Protests were planned for Monday in the country's second city of Mandalay, activist Myat Thu said, while residents in Yangon said demonstrations were planned in two areas of the city. Violence also broke out in other parts of Yangon as protests ran late into Sunday night.
The latest deaths would bring the toll from the protests to 126, the AAPP said. It said more than 2,150 people had been detained by Saturday. More than 300 have since been released.
Tom Andrews, the United Nations human rights investigator on Myanmar, appealed for UN member states to cut the supply of cash and weapons to the military.
"Heartbroken/outraged at news of the largest number of protesters murdered by Myanmar security forces in a single day. Junta leaders don't belong in power, they belong behind bars," he said on Twitter.
China's embassy described the situation as "very severe" after the attacks on the Chinese-financed factories.
No group claimed responsibility for burning the factories.