- Ambulance driver Than Lwin Oo told AFP he had sent the bodies of the 18-year-olds to the mortuary at Bago's main hospital.
YANGON: Myanmar security forces shot dead at least six protesters Sunday in the bloodiest action so far to smother opposition to the military coup four weeks ago.
The junta is battling to contain a massive street movement demanding it yield power and release ousted civilian leader Aung San Suu Kyi, who was detained along with top political allies at the start of the month.
Police and soldiers had already fired rubber bullets, tear gas and water cannon on demonstrations in recent weeks in an effort to bring the civil disobedience campaign to heel, with live rounds used in some isolated cases.
Large numbers were again mobilised on Sunday morning to scatter crowds in several parts of the country, after online calls for protesters to once again flood the streets.
Three men were killed and at least 20 others injured when security forces moved on a rally in the southern coastal hub of Dawei, a volunteer medic and a media outlet based in the city said.
Rescue worker Pyae Zaw Hein said the trio were "shot dead with live rounds", while the injured were hit by rubber bullets.
"More wounded people keep coming in," he told AFP.
Two teenagers were also gunned down in Bago, a two-hour drive north of commercial capital Yangon.
Ambulance driver Than Lwin Oo told AFP he had sent the bodies of the 18-year-olds to the mortuary at Bago's main hospital.
The deaths were confirmed by media based in the town.
Officers in Yangon began dispersing small crowds minutes before the slated beginning of the day's protest, with one 23-year-old shot dead in the city's east.
"His wife is heartbroken," Win Ko, a social worker who visited the man's widow, told AFP. "She's three months pregnant."
Local lawmaker Nyi Nyi who was ousted from his parliamentary seat by the coup, confirmed the details of the death in a Facebook post.
Elsewhere in the city, protesters took up positions behind barricades and wielded homemade shields to defend themselves against the onslaught, with police using tear gas to clear some rallies.
One man in Mandalay was taken to hospital in critical condition after a projectile pierced his helmet and lodged in his brain.
A doctor in the city, Myanmar's second-largest, said it was not known whether the 41-year-old had been struck by a live round or a rubber bullet.
At least one journalist documenting Sunday's assaults by security forces was beaten and detained further north in Myitkyina, a city at the headwaters of the Irrawaddy river, according to local outlet The 74 Media.
Another reporter was shot with rubber bullets while covering a protest in the central city of Pyay, their employer said.
Since the February 1 military takeover, Myanmar has been roiled by giant demonstrations and a civil disobedience campaign encouraging civil servants to walk off the job.
Sunday's crackdown followed a similar wave of violent action against angry but largely peaceful anti-coup rallies around the country a day earlier.
Several journalists documenting Saturday's assaults by security forces were detained, including an Associated Press photographer in Yangon.
More than 850 people have been arrested, charged or sentenced since the coup, according to the Assistance Association for Political Prisoners monitoring group.
But the weekend crackdown was expected to raise that number dramatically, with state newspapers reporting 479 arrests on Saturday alone.
International condemnation of the coup has been fierce, with the United States, the European Union and other major powers denouncing violence against protesters.
Suu Kyi has not been seen in public since she was taken into custody during pre-dawn raids in the capital Naypyidaw as the coup was launched.
A court hearing will be held on Monday for the ousted leader, who faces obscure charges for possession of unregistered walkie-talkies and violating coronavirus restrictions on public gatherings.
But her lawyer Khin Maung Zaw told AFP he had still been unable to meet with Suu Kyi ahead of the hearing.
"As a lawyer, I put my trust in the court," he said. "But in this period of time anything can happen."
State media announced Saturday that the junta had sacked the country's United Nations envoy, who gave an impassioned plea for help on behalf of Myanmar's ousted civilian government.
Before Sunday, at least five people had been killed since the army takeover -- four from injuries sustained at anti-coup demonstrations.
One police officer also died while attempting to quell a protest, the military has said.