Some 300 Myanmar MPs have urged the United Nations to investigate "gross human rights violations" they allege have been carried out by the military.
In a letter to the UN Human Rights Council in Geneva, MPs accused Myanmar's security forces of shooting anti-coup protesters.
Earlier, the UN human rights envoy to Myanmar said there was evidence that forces had used live bullets.
The council later called on Myanmar to allow access for human rights monitors.
Protests continued on Friday in defiance of a plea from Gen Min Aung Hlaing, who the army installed as the country's military leader on 1 February.
He called for "unity" to prevent "disintegration" as the country marked the Union Day holiday.
Demonstrators are demanding the release of detained elected leaders, including Aung San Suu Kyi.
As protesters took to the streets again, there were some reports of rubber bullets being fired by police.
There have also been reports of security forces visiting the homes of medical professionals and attempting to detain them for questioning over involvement in a civil disobedience movement. Several videos shared on Facebook were said to show family members arguing with the security forces at their properties.
Separately, Facebook said on Friday it would restrict content by Myanmar's military because a number of accounts had "continued to spread misinformation".
What happened at the UN meeting?
At an emergency meeting on Friday, Britain's ambassador to the United Nations in Geneva, Julian Braithwaite, read out the contents of a letter on behalf of Myanmar's elected parliamentarians. He urged the Human Rights Council to "support our efforts" in highlighting alleged abuses by carrying out an investigation.
Braithwaite said the military coup had resulted in the arrest of civilian leaders, the reported shooting of demonstrators and "restrictions on people's freedom of speech".
Speaking at the same meeting, Thomas Andrews - the United Nations human rights investigator for Myanmar - said that while investigators had been denied access to the country, there were "growing reports and photographic evidence" that live ammunition had been used against protesters in breach of international law.
Andrews said the people of Myanmar had invested their hope in the UN, and needed more than a statement on paper. He called on the UN - through the security council - to consider economic sanctions against Myanmar, a ban on arms exports, and a travel ban on military leaders.
The UN Human Rights Council's 47 members then voted to adopt a resolution demanding the "immediate and unconditional" release of political detainees and the restoration of Myanmar's elected government.
The resolution, put forward by the UK and the European Union, also called for the lifting of restrictions on the internet, unimpeded access for the delivery of UN humanitarian aid, and access for UN human rights monitors.
What about Myanmar's Union Day?
On Thursday, in a TV address to the nation, Gen Hlaing said those protesting had been "incited" and again asked them to work for the country without "focusing on the emotion".
The military marked Union Day by granting amnesty to, and ordering the release of, more than 23,000 prisoners, including 55 foreigners. Mass pardons are common on national days, often to reduce numbers in overcrowded prisons.
Union Day celebrates the signing in 1947 of an agreement between the government under Suu Kyi's father, Aung San, and the Shan, Kachin and Chin people that marked the unification of the republic.
A student activist in Mandalay, Tayzar San, told the BBC he feared the prisoners were being released to attack protesters.
"The people have a very bad precedent. In 1988, the military junta released the pro-military prisoners and they disturbed our people's peaceful demonstrations," he said.
The crackdown on the 1988 pro-democracy uprising is believed to have left thousands dead.
In his address, Gen Hlaing called on people to stay in their houses, citing the dangers of the pandemic.
But the protests continued on Friday. They remained mostly peaceful, although Radio Free Asia footage showed police charging at protesters in the city of Mawlamine.
A Red Cross official told Reuters three people were injured by rubber bullets.
Protests have also continued in the biggest city, Yangon, the capital Nay Pyi Taw, the coastal town of Dawei, and Myitkyina in northern Kachin state, among others.
Earlier this week, 19-year-old Mya Thwe Thwe Khaing was shot in the head and seriously injured when police tried to disperse protesters using water cannon, rubber bullets and live rounds.
She remains on a ventilator in hospital in a critical condition. The wound was consistent with one from live ammunition, rights groups said.
The US has been among those demanding a return to democracy and the release of civilian leaders. It has targeted a number of officials and companies with sanctions.
The military seized control on 1 February following a general election which Suu Kyi's National League for Democracy won by a landslide.
The armed forces had backed the opposition, which was demanding a rerun of the vote. It claimed widespread fraud, an accusation rejected by the electoral commission.
The coup was staged as a new session of parliament was set to open.
Suu Kyi is under house arrest and has been charged with possessing illegally imported walkie-talkies. Many other NLD officials have also been detained.
- BBC