YANGON, Myanmar (AP) — Security forces in Myanmar have again used force to disperse anti-coup protesters, a day after the U.N. special envoy urged the Security Council to take action to quell junta violence that this week left more than 50 demonstrators dead and scores injured. Protests were reported Saturday morning in the biggest city of Yangon, where stun grenades and tear gas were used against protesters. On Wednesday, 18 people were reported killed there. Rallies also took place in several other cities. 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. The International Federation of Red Cross and Red Crescent Societies urged immediate protection for all volunteers.