Five people died when members of Myanmar's security forces rammed a car into an anti-coup protest on Sunday morning in Yangon.
Witnesses told Reuters that dozens more people were injured, and local news portal Myanmar Now reported that 15 were arrested.
Photos and videos on social media showed the vehicle that crashed through the protesters, and bodies lying on the road.
The flash-mob protest was rammed by the car minutes after it started, witnesses said.
“I got hit and fell down in front of a lorry. A soldier beat me with his rifle but I defended and pushed him back," a protester told Reuters.
"Then he immediately shot at me as I ran away in a zigzag pattern. Fortunately, I escaped.”
The car driven by soldiers hit the crowd from the back, two witnesses said, and followed the scattered protesters, arresting and beating them.
Some demonstrators suffered serious head wounds. Others were left unconscious, witnesses said.
A spokesman for the junta did not answer calls seeking comment on Sunday.
Another demonstration was later held in Yangon, the country's biggest city, despite the morning violence.
Protests against the country's military are continuing despite the deaths of more than 1,300 people since the February 1 coup. The scattered protests are often staged by small groups opposed to the overthrow of an elected government led by Nobel laureate Aung San Suu Kyi.
The opposition's shadow government said it was heart-broken to see peaceful protesters killed and injured.
“We will strongly respond to the terrorist military who brutally, inhumanly killed the unarmed peaceful protesters,” the National Unity Government's defence ministry said after Sunday's attack.
Protesters 'instigated violence', military claims
Myanmar's military has said it staged the coup because a November election won by Ms Suu Kyi's party was rigged. The country's election commission has dismissed the claim.
Clashes with ethnic-minority insurgents in remote frontier regions in the north and east have intensified significantly since the coup, displacing tens of thousands of civilians, according to UN estimates.
Ms Suu Kyi, 76, faces a dozen cases against her, including incitement and breaches of Covid-19 protocols.
She has denied all the charges.