Myanmar pro-democracy activists pledged on Thursday to hold more demonstrations after the United Nations said 38 people had been killed in the most violent day of unrest since last month's military coup.
Police and soldiers opened fire with live rounds on Wednesday with little warning, witnesses said.
The bloodshed occurred a day after neighboring countries had called for restraint in the aftermath of the military's overthrow of the elected government of Aung San Suu Kyi.
"We know that we can always get shot and killed with live bullets but there is no meaning to staying alive under the junta so we choose this dangerous road to escape," activist Maung Saungkha told Reuters.
"We will fight the junta in any way we can. Our ultimate goal is to remove the junta system from the roots," said Maung Saungkha, who said his General Strike Committee of Nationalities group planned to hold a protest on Thursday.
Social media posts from other activists said at least 2 other demonstrations were also planned in parts of Yangon.
United Nations special envoy on Myanmar, Christine Schraner Burgener, said in New York that Wednesday was the "bloodiest day" since the February 1 coup with 38 deaths, bringing the total toll to more than 50 as the military tries to cement its power.
A rights group and some media have given different numbers of wounded and killed after Wednesday's violence. The dead included 4 children, an aid agency said. Local media reported that hundreds of protesters were arrested.
A spokesman for the ruling military council did not answer telephone calls seeking comment.
Suu Kyi's National League for Democracy party said in a statement that flags would fly at half mast at its offices to commemorate the dead.
Schraner Burgener said she warned Myanmar deputy military chief Soe Win that the military was likely to face strong measures from some countries and isolation in retaliation for the coup.
"The answer was: 'We are used to sanctions, and we survived'," she told reporters. "When I also warned they will go (into) isolation, the answer was: 'We have to learn to walk with only few friends'."
The UN Security Council is due to discuss the situation on Friday in a closed meeting, diplomats said.
US State Department spokesman Ned Price said the United States was "appalled" by the violence and was evaluating how to respond.
The United States has told China it expects Beijing to play a constructive role, the spokesman said. China has declined to condemn the coup, with Chinese state media calling it a "major cabinet reshuffle".
The European Union said the shootings of unarmed civilians and medical workers were clear breaches of international law. It also said the military was stepping up repression of the media, with a growing number of journalists arrested and charged.
'EVERYTHING WILL BE OK'
In Yangon, witnesses said at least 8 people were killed on Wednesday, while local media reported 6 were killed in the central town of Monywa.
"I heard so much continuous firing. I lay down on the ground, they shot a lot," protester Kaung Pyae Sone Tun, 23, told Reuters.
Save the Children said 4 children were killed including a 14-year-old boy who Radio Free Asia reported was shot dead by a soldier on a passing convoy of military trucks. The soldiers loaded his body onto a truck and left, according to the report.
Security forces breaking up protests in Yangon detained about 300 protesters, the Myanmar Now news agency reported.
Images of a 19-year-old woman, one of two shot dead in Mandalay, showed her wearing a T-shirt that read "Everything will be OK".
Police in Yangon ordered three medics out of an ambulance and beat them with gun butts and batons, video broadcast by US-funded Radio Free Asia showed. Reuters was unable to verify the video independently.
The military justified the coup by saying its complaints of voter fraud in the November 8 vote were ignored. Suu Kyi's party won by a landslide, earning a second term.
The election commission said the vote was fair.
Junta leader Senior General Min Aung Hlaing has pledged to hold new elections but given no time frame.
Suu Kyi, 75, has been held incommunicado since the coup but appeared at a court hearing via video conferencing this week and looked in good health, a lawyer said.
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