Police in Myanmar launched their most sweeping crackdown in three weeks of nationwide protests against military rule on Saturday, arresting hundreds of people and shooting and wounding at least one person.

State television announced that Myanmar’s UN envoy had been fired for betraying the country, a day after he urged the UN to use “any means necessary” to reverse the February 1 coup that ousted elected leader Aung San Suu Kyi.

Myanmar has been in turmoil since the army seized power and detained Suu Kyi and much of her party leadership, alleging fraud in a November election her party won in a landslide.

The coup, which stalled Myanmar’s progress towards democracy, has brought hundreds of thousands of protesters onto the streets and drawn condemnation from western countries, with some imposing limited sanctions.

Police were out in force early on Saturday, taking up positions at usual protest sites in the main city of Yangon.

Confrontations developed as people came out despite the police operation, chanting and singing. They scattered into side streets and buildings as police advanced, firing tear gas, setting off stun grenades and shooting guns into the air. Police set upon some people with clubs, witnesses said.

State-run MRTV television said more than 470 people had been arrested across the country. It said police had given warnings before dispersing people with stun grenades.

“People blocked the roads without reason. Among those arrested, we will scrutinise those who organise the protests and take tough action,” it said.

One woman was shot and wounded in the central town of Monwya, local media 7Day News and an emergency worker said. 7Day and two other media organisations had earlier reported that she was dead. Junta leader General Min Aung Hlaing has said authorities have been using minimal force.