At least 38 people were killed in Myanmar on Wednesday in what the UN described as the “bloodiest day” since the coup took place a month ago.
Reports from inside Myanmar spoke of security forces opening fire on large crowds in a number of cities, including Yangon, with little warning.
Two boys, aged 14 and 17, were among those who were killed, Save the Children said.
Christine Schraner Burgener, UN envoy to Myanmar said there was shocking footage coming out of the country.
She said one video clip showed police beating an unarmed volunteer medical crew. Another showed a protester being shot and probably killed on the street, she said.
“I asked some weapons experts and they could verify to me, it’s not clear but it seems that the police weapons like 9mm submachine guns, so live ammunition,” she said.
— Myanmar Now (@Myanmar_Now_Eng) March 4, 2021
Schraner Burgener said at least 50 people had now been killed “and many wounded” since the coup began.
Ms Schraner Burgener has urged the UN to take “very strong measures” against the generals. The UN envoy warned of such punitive action in a conversation with Myanmar’s deputy military chief.
Meanwhile the country’s military said it was ready to withstand sanctions and isolation after its coup.
Wednesday’s violence left the US “appalled”, State Department spokesman Ned Price said. “We call on all countries to speak with one voice to condemn the brutal violence by the Burmese military against its own people.”
He urged China, historically a close ally of Myanmar, to bring its influence to bear on the country’s military.
The UN Security Council has voiced concern over the situation, but stopped short of condemning the coup because of opposition by Russia and China, who view the matter as an internal affair.
Meanwhile, Pope Francis called for dialogue to “prevail over repression”.
Foreign ministers of neighbouring South East Asian nations held a special meeting on Tuesday about the situation in Myanmar.
But although they urged restraint, only some of the ministers pressed the military junta to release Ms Suu Kyi.
The military says it seized power because of alleged fraud in November’s general elections, which saw Ms Suu Kyi’s National League for Democracy (NLD) party win a landslide victory.
But the military has provided no proof of these allegations.