Among the wounded was an 80-year-old monk who witnesses said was beaten about the head by security forces.
The elderly monk has participated in the daily anti-junta protests in Rangoon although he cannot walk and has to be carried.
Hospital officials have refused to comment on any injuries stemming from the crackdown.
Despite the violence, tens of thousands of people remained on the streets of Yangon, scattered across the city, witnesses said.
In the outlying township of Ahlone, about 300 monks protested but were blocked by armed soldiers who began firing over their heads, witnesses said.
The monks urged the people to stay away from the protest, but when the bullets started whizzing overhead, hundreds of people sat on the ground around the monks in a show of solidarity, the witnesses said.
"I felt so sorry when I saw this scene. I've never seen this kind of violence. I feel so sorry for the monks," one woman said by telephone from Ahlone.
At the Sule Pagoda in downtown Rangoon, security forces tried to use tear gas and warning shots to disperse the crowd, but thousands kept returning to taunt the soldiers.
As the day wore on, some protesters began to throw stones at the soldiers, who responded with more warning shots, witnesses said.
At least one man was seen being carried away after he was injured when thousands of people began running from the tear gas.