Much of the country has been in open revolt since troops deposed civilian leader Aung San Suu Kyi on February 1, with disparate strands of Myanmar society uniting to protest against a return to military rule.

Security forces have steadily stepped up the show -- and use -- of force, by deploying troops against peaceful protesters, and firing tear gas, water cannon and rubber bullets.

A rally on February 9 in Myanmar's capital Naypyidaw turned violent when police fired rubber bullets at demonstrators, though doctors at the hospital later told AFP that at least two people had been critically wounded by live rounds.

Mya Thwate Thwate Khaing, who turned 20 last Thursday as she lay unconscious in a hospital bed, was shot in the head. A doctor confirmed her death Friday, adding that her body will be examined as it is a "case of injustice".

The young protester, a grocery store worker, is the first official death from the anti-coup movement since hundreds of thousands started gathering across the country two weeks ago to protest Myanmar's return to military rule.

She has since become a symbol of resistance for protesters, hoisting her photos high in demonstrations and even unfurling a massive banner of artwork from a bridge showing the moment she was shot.

Her sister Poh Poh told reporters on Friday: "Please all join this protest movement to be more successful. That's all I want to say."

She added that the burial will be on Sunday.

Military spokesman-turned-deputy information minister Zaw Min Tun said this week that authorities were investigating the case.

He also said a police officer had died in Mandalay after a confrontation with protesters Sunday.

- Sanctions from UK, Canada -

Mya Thwate Thwate Khaing's death comes after an overnight announcement from Britain -- Myanmar's former colonial power -- and Canada that several generals would be sanctioned over their roles in the junta's security forces.

Freezing the assets of three top generals, the UK also said it was beginning a review to stop British businesses working with the military.

Canada sanctioned nine Myanmar military officials and accused the junta of engaging "in a systemic campaign of repressions through coercive legislative measures and use of force".

These actions come after US President Joe Biden last week announced Washington would cut off the generals' access to $1 billion in funds in the US.

Burma Campaign UK's Wai Hnin Pwint Thon said she was encouraged by the UK's review of severing business ties with military-linked companies as "it will have an impact" if it hits coffers filled from lucrative gems, beer, and banking sectors.

But so far, "it is more a symbolic gesture than an effective one", she said.

Her famed activist father Mya Aye was detained the night of the coup, and she said her family still has no news of his whereabouts.

- Internet shutdowns and night arrests -

The country endured its fifth consecutive night of "curfew-style shutdowns", according to monitoring group NetBlocks, reporting that the internet returned around 9 am local time.

By noon, tens of thousands -- including railway workers and teachers dressed in their uniforms to show they are boycotting work -- amassed across Yangon, Myanmar's largest city, carrying posters of Suu Kyi that read "Free our leader".

"Don't go to the office!" they chanted. "Go strike! Go strike!"

In the northern city of Myitkyina, a small group of protesters were forcefully dispersed by police and military wielding batons, according to video posted online and witnesses.

One teacher who was there -- and now in hiding for fear of arrest -- said she saw dozens arrested in the scuffle, including two of her colleagues.

"They arrested those who tried to take photos and videos... this is real injustice," she told AFP.

Before Friday, more than 520 people have been arrested, according to the Assistance Association for Political Prisoners (AAPP) monitoring group, many of them civilians taking part in the so-called "Civil Disobedience Movement".

The junta has justified its power seizure by alleging widespread electoral fraud in November's elections, which Suu Kyi's party won in a landslide.

The Nobel laureate -- who has not been seen since she was detained in dawn raids -- has been hit with an obscure charge for possessing unregistered walkie-talkies, and for flouting coronavirus restrictions during campaign events.

Her hearing is expected on March 1.