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.