Security forces in Myanmar have made mass arrests and appeared to use lethal force on Sunday as they intensify their efforts to break up protests a month after the military staged a coup.

There were reports of gunfire as police in Yangon, the biggest city, fired tear gas and water cannons while trying to clear the streets of demonstrators who are seeking to have the elected government of Aung San Suu Kyi restored to power.

A violent crackdown also occurred in Dawei, a much smaller city in southeastern Myanmar, where local media reported at least three people were killed during a protest march.

The Yangon protesters later regrouped, with plans to march to a police station to demand the release of medical students.

According to a report from the independent Assistance Association of Political Prisoners, as of Saturday, over 800 people had been arrested, charged or sentenced at one point in relation to the coup, and over 700 were being detained or sought for arrest.