Several other serious injuries were also reported. The shootings occurred near Mandalay’s Yadanabon dock, where tear gas and rubber bullets were used on protesters earlier in the day.
The Irrawaddy news website also confirmed the deaths on social media.
Security forces had been increasing their pressure against anti-coup protesters earlier Saturday, using water cannons, tear gas, slingshots and rubber bullets against demonstrators and striking dock workers in Mandalay.
At least five people were injured by rubber bullets and had to be carried away in ambulances, according to an Associated Press journalist who witnessed the violence.
Some 500 police and soldiers descended on the area near Yadanabon dock after dock workers joined the national civil disobedience movement, refusing to work until the military junta that seized power in a Feb. 1 coup reinstates the democratically elected government.
Protesters and residents were forced to flee the neighbourhood amid the violence, as security forces chased after them.
There were reports of sounds that resembled gunfire. A group of journalists was forced to flee after being hit with tear gas and slingshot projectiles.