Myanmar's deadly crackdowns on protests are worsening here's what you need to know

Security forces in Myanmar opened fire and made mass arrests on Sunday as they sought to break up protests against the military's seizure of power, whilea United Nationshuman rights official said there was"credible information" that 18 people were killed and 30 were wounded.

That would be the highest single-day death toll among protesters who are demanding that the elected government of Aung San Suu Kyi be restored to power after being ousted by a Feb. 1 coup.

Gunfire was reported almost as soon as the protests began Sunday morning in Yangon, the country's biggest city, as police also fired tear gas and water cannons while trying to clear the streets. Photos of shell casings from live ammunition used in assault rifles were posted on social media.

In the morning, medical students marched in Yangon near the Hledan Center intersection, which has become the gathering point for protesters who then fan out to other parts of the city.

Videos and photos showed protesters running as police charged at themand residents setting up makeshift roadblocks to slow their advance. Some protesters managed to throw tear gas canisters back at police. Nearby, residents were pleading with police to release those they picked up from the street and shoved into police trucks to be taken away. Dozens or more were believed to be detained.

A violent crackdown also occurred in Dawei, a much smaller city in southeastern Myanmar, where local media reported that at least three people were killed during a protest march. The fatalities could not immediately be independently confirmed, though photos posted on social media showed a wounded man in the care of medical personneland later laid out in a bed under a blanket with flowers placed on top.

The independent Assistance Association of Political Prisoners reported it was aware that about 1,000 people were detained Sunday, of whom they were able to identify 270. That brought to 1,132 the total number of people the group has confirmed have been arrested, charged or sentenced since the coup.

Confirming reports of protesters' deaths and arrests has been difficult amid the chaos and general lack of news from official sources.

Whathas happened in recent days?

Supporters ofSuu Kyihave been taking to the streets of Myanmar for weeks.The protest movement has embraced non-violence and only occasionally gotten into shoving matches with police and thrown bottles at them when provoked.

Authorities have cracked down on demonstrators, often violently, and made hundreds of arrests.

Meanwhile, in an emotional speech on Friday at the UN General Assembly in New York, Ambassador Kyaw Moe Tun declared that he represented Suu Kyi's "civilian government elected by the people" and supported the struggle against military rule.

He urged all countries to issue public statements strongly condemning the coupand to refuse to recognize the military regime. He also called for stronger international measures to stop violence by security forces against peaceful demonstrators.

Who is Aung San Suu Kyi?

Suu Kyi is by far the country's most popular politicianand became Myanmar's de facto leader after her party won the 2015 elections, though the constitution barred her from being president.

She hadbeen a fierce antagonist of the army, and her efforts to promote democracy while they put her under house arrest won her the Nobel Peace Prize. Nevertheless, once in power,Suu Kyi had to balance her relationship with the country's generals and even went on the international stage to defend their crackdown on Rohingya Muslims in the country's west a campaign the U.S. and others have labelled genocide. That has left her reputation internationally in tatters.

Suu Kyi's National League for Democracy party would have been installed for a second five-year term in office after a recent election, but the army blocked parliament from convening and detained her and President Win Myint, as well as other top members of Suu Kyi's government. She is currently being detained over charges ofillegally possessing walkie-talkies an apparent attempt to provide a legal veneer for her house arrest.

Why was there a coup?

The Feb. 1 coup reversed years of slow progress toward democracy after five decades of military rule.

The military said it took power because last year's polls were marred by massive irregularities. The election commission before the military seized power had refuted the allegation of widespread fraud. But the junta dismissed the old commission's members and appointed new oneswho on Friday annulled the election results.

Power has been handed over to military chief General Min Aung Hlaing, whohas imposed a state of emergency for a year.

How is the international community reacting?

Many countries have condemned the coup, which derailed years of efforts to establish democracy in the poverty-stricken country and raised even more questions over the prospect of returning a million Rohingya refugees.

"No regime that would use force to suppress the democratically expressed will of its people can be legitimate," Marc Garneau, Canada's foreign affairs minister, said in a statement on Sunday. "Those responsible for this violence will be held to account, and Canada will consider additional measures in response. We stand with the people of Myanmar."

The Office of the UN High Commissioner for Human Rights said on Sunday that it"strongly" condemns the "escalating violence" and called on the military to "immediately halt the use of force against peaceful protesters."