At least 20 people were shot, including one whose condition is critical, as security forces opened fire at protesters on Tuesday in Kale, northwestern Sagaing region, a medic has said.

Tens of thousands of anti-coup protesters gathered in the town from around 10am. About half an hour later, a soldier who was positioned inside a building nearby shot into the crowd, an emergency worker who witnessed the incident told Myanmar Now.

“The police advanced towards the protesters with water cannon and a police truck to break up the crowd with force,” he said. “A soldier behind them shot two rounds of bullets, but into the air according to what I saw.”

“At the same time, a soldier shot from inside a building nearby with what appeared to be live bullets,” said the medic, who asked not to be named for fear of reprisals.

Of those shot in Kale, one was in a “critical condition” after being hit in the abdomen, the medic added. “The patient is not ready to operate on because he had eaten recently and we are waiting for a surgeon from Tedim.”

Tedim, a town in neighbouring Chin state, is nearly 70km from Kale.

Two others - one who was hit in the chest and another who was hit in the thigh - were severely injured but now in a stable condition. “Doctors found the bullets,” he said.

Striking doctors and medics are treating the injured at a private hospital.

A video posted on social media showed a line of riot police in Kale advancing at protesters with a police truck following behind them. The protesters, equipped with homemade shields, then began repelling the police, forcing them to retreat.

At around 2pm, tensions had subsided but security forces were fanning out around the area, the emergency worker said.

“Confrontations between protesters and police are normal. It happens in many countries. But targeting them from a place and shooting into the crowd purposely is sickening,” he said.

The Assistance Association for Political Prisoners estimates at least 30 people have been killed in attacks by security forces against anti-military protesters since the February 1 coup.