Yesterday was the bloodiest day in Myanmar since a military junta seized power there one month ago. According to the United Nations Human Rights Office, at least 18 people were killed and more than 30 wounded after security forces fired live ammunition into crowds of peaceful demonstrators in several cities across the country.

 "The people of Myanmar have the right to assemble peacefully and demand the restoration of democracy," U.N. Human Rights Office spokesperson Ravina Shamdasani said in a statement. "These fundamental rights must be respected by the military and police, not met with violent and bloody repression. Use of lethal force against non-violent demonstrators is never justifiable under international human rights norms."

In additional to live rounds, police also used tear gas to disperse thousands of protesters in major cities including Yangon, Dawei and Mandalay. Gruesome images widely shared on social media showed people running for cover as victims lay bleeding on the ground.

 In addition to using force on protesters, the military detained at least 85 medical personnel and students and seven journalists Sunday, the U.N. reported. Since the beginning of the coup on Feb. 1, more than 1,000 people have been "arbitrarily arrested," the U.N. says — and some are still unaccounted for.

 Meanwhile, state-run media said police were taking action in order to "protect the safety of people, the rule of law and community peace." The government-run Global New Light of Myanmar reported that police are working to discover who is leading the protests, and will take "serious action" against them.

 On Friday, Myanmar's ambassador to the U.N., who was appointed under the country's civilian government before the coup, pleaded with the world to help. "We still need the strongest possible action from the international community to immediately end the military coup," Kyaw Moe Tun said. He was removed from his position as ambassador the next day.