At least 91 civilians were killed across Myanmar on Saturday, according to a tally by the independent Myanmar Now news outlet, as the military junta continued to crack down on peaceful protests.

The killings in 40 towns and cities across the country would represent the bloodiest day of protests since a military coup last month. CNN has been unable to independently confirm the number of people killed. The lethal crackdown came on the country's Armed Forces Day. Senior Gen. Min Aung Hlaing, the junta leader, said during a parade in the capital Naypyitaw to mark the event that the military would protect the people and strive for democracy, Reuters reported. State television had said on Friday that protesters risked being shot "in the head and back." Despite this, demonstrators against the February 1 coup came out on the streets of Yangon, Mandalay and other towns.

The United Nations office in Myanmar condemned the violence Saturday in a strongly worded statement. "The United Nations in Myanmar is horrified by the needless loss of life today with reports of dozens of people shot dead by the military across the country, in the bloodiest day since the coup," the office said. "The violence is completely unacceptable and must stop immediately. Those responsible must be held to account. "As the Special Envoy on Myanmar, Christine Schraner Burgener has said, ensuring peace and defending the people should be the responsibility of any military, but the Tatmadaw has turned against its own people." The Tatmadaw is the official name for Myanmar's armed forces. According to the latest tally by the nonprofit Assistance Association for Political Prisoners, at least 328 people have been killed in Myanmar since the military coup on February 1.

A boy reported by local media to be as young as five was among at least 29 people killed in Mandalay. At least 24 people were killed in Yangon, Myanmar Now said, according to Reuters. "Today is a day of shame for the armed forces," Dr. Sasa, a spokesman for CRPH, an anti-junta group set up by deposed lawmakers, told an online forum. Meanwhile, one of Myanmar's two dozen ethnic armed groups, the Karen National Union, said it had overrun an army post near the Thai border, killing 10 people -- including a lieutenant colonel -- and losing one of its own fighters, Reuters reported. A military spokesman did not respond to calls from the news agency seeking comment on the killings by security forces or the insurgent attack on its post. "They are killing us like birds or chickens, even in our homes," said Thu Ya Zaw in the central town of Myingyan, where at least two protesters were killed, according to Reuters. "We will keep protesting regardless... We must fight until the junta falls."