Myanmar's military has carried out airstrikes against ethnic minority armed forces supporting anti-coup protesters, despite calling for a ceasefire.
The military proposed a one-month truce starting Thursday, but conducted airstrikes in Karen State in the southeast on Friday.
The military also deployed ground troops. The Karen ethnic armed group is reportedly fighting back.
About 20,000 residents have evacuated. Some are fleeing toward the border with Thailand.
A local human rights group says 550 people have been killed in the crackdown since the February 1 coup.
People continued to protest nationwide on Friday. Many laid flowers in honor of the dead.
In a statement issued via state media on Friday evening, the military hit back against the UN secretary-general's special envoy on Myanmar, who said on Wednesday that "a bloodbath is imminent."