Hundreds of young Myanmar protesters who had been trapped by security forces in the Sanchaung district of Yangon have been able to leave the area, activists said on Tuesday.

Earlier, UN chief Antonio Guterres called on Monday for the safe release of the protesters, said his spokesman.

"Many of those trapped are women who were peacefully marching in commemoration of International Women's Day," the spokesman said.

According to the UN rights office "police began shooting and making arrests" in Yangon around 10:00 p.m. Monday, although it was unclear if they were arresting trapped protesters or newly arrived demonstrators.