YANGON, Myanmar (AP) — Demonstrators defied growing violence by Myanmar security forces and staged more anti-coup rallies Friday, while the U.N. special envoy for the country called for urgent Security Council action, saying about 50 peaceful protesters were killed and scores were injured in the military’s worst crackdowns this week.

The escalation of violence has put pressure on the world community to act to restrain the junta, which seized power on Feb. 1 by ousting the elected government of Aung San Suu Kyi.

Large protests against military rule have occurred daily in many cities and towns. Security forces escalated their crackdown with greater use of lethal force and mass arrests. At least 18 protesters were shot and killed Sunday and 38 on Wednesday, according to the U.N. Human Rights Office. More than 1,000 have been arrested, the independent Assistance Association for Political Prisoners said.

Protests continued in the biggest cities of Yangon and Mandalay and elsewhere Friday. They were met again with force by police, and gunfire was heard. In Mandalay, Zaw Myo was fatally shot as the 26-year-old and other residents sought to protect a march by a group of engineers.

U.N. special envoy Christine Schraner Burgener said in her briefing to a closed Security Council meeting that council unity and “robust” action are critical “in pushing for a stop to the violence and the restoration of Myanmar’s democratic institutions.”

“We must denounce the actions by the military,” she said in her briefing, as released by the U.N. “It is critical that this council is resolute and coherent in putting the security forces on notice and standing with the people of Myanmar firmly, in support of the clear November election results.”

Schraner Burgener reiterated an earlier appeal to the international community not to “lend legitimacy or recognition to this regime that has been forcefully imposed and nothing but chaos has since followed.”