Myanmar police opened fired on Sunday on protests against military rule, killing at least four people and wounding several on the second day of a crackdown on demonstrations across the country, a doctor and a politician said.

A woman also died after police broke up a teachers' protest with stun grenades in the main city of Yangon, though the cause of her death was not known, her daughter and a colleague said.

Myanmar has been in chaos since the army seized power and detained elected government leader Aung San Suu Kyi and much of her party leadership on Feb. 1, alleging fraud in a November election her party won in a landslide.