Activists say 38 protesters have been killed in one of the bloodiest days yet in Myanmar since the military toppled the government.
Security forces opened fire in an area of Myanmar’s largest city, Yangon, with protesters using sticks and knives.
The military declared martial law in the area after Chinese businesses were attacked. Protesters believe China is giving support to the Burmese military.
Myanmar has been gripped by protests since the military coup on 1 February.
Military rulers have detained Aung San Suu Kyi, the country’s civilian leader and head of the National League for Democracy (NLD) party.
The NLD won a landslide in last year’s election but the military alleged there had been widespread fraud.
Some of the ousted MPs have refused to accept last month’s coup and have gone into hiding.
In his first public address, their leader Mahn Win Khaing Than urged protesters to defend themselves against the military crackdown during what he called a “revolution”.
“This is the darkest moment of the nation and the moment that the dawn is close,” he said, adding: “The uprising must win.”
At least 21 people were reportedly killed in Yangon on Sunday. Further deaths and injuries were reported elsewhere in the country. The Assistance Association for Political Prisoners (AAPP) monitoring group said the day’s death toll was at least 38.
Medical workers said the number of people killed in the Yangon area of Hlaing Tharyar was likely to rise, with dozens suffering gunshot wounds.
The junta has declared martial law in Hlaing Tharyar and neighbouring Shwepyitha after China said Chinese factories in the area had been targeted and demanded protection.
Beijing said people armed with iron bars, axes and petrol had set alight and damaged 10 Chinese facilities – mostly clothing production or storage factories – in Yangon. A Chinese hotel was also attacked.
On its Facebook page the Chinese embassy said some “factories were looted and destroyed and many Chinese staff were injured and trapped”.
The embassy urged Myanmar to “take further effective measures to stop all acts of violence, punish the perpetrators in accordance with the law and ensure the safety of life and property of Chinese companies and personnel in Myanmar”.
The military-owned Myawaddy Media reported that firefighters had been hindered in their response to the blazes by people blocking their routes.