Burmese security forces have cracked down on protesters occupying a copper mine, using water cannons and other devices to break up the rally hours before opposition leader Aung San Suu Kyi was expected to hear their grievances.
Unexplained fires engulfed the protest camps at the Letpadaung mine in north western Burma and dozens of Buddhist monks and villagers were injured, according to several protesters.
Those who fled the site emerged with burns and charred clothing on their bodies.
"Around 2:30am police announced they would give us 5 minutes to leave," said protester Aung Myint Htway, a peanut farmer whose face and body was covered with black spots where his skin was burned.
He said police fired water cannons first and then fired from what he and others called flare guns.
"They fired black balls that exploded into fire sparks. They shot about six times. People ran away and they followed us," he said, still writhing hours later from pain. "It's very hot."
The government ordered protesters earlier this week to evacuate the mine by yesterday or face legal action.
The protesters, who had set up six camps at the site, say the Letpadaung mine near the town of Monywa is causing environmental, social and health problems.
The protest is the latest major example of increased activism by citizens since an elected government took over last year following almost five decades of repressive military rule.
"This is unacceptable," said Ottama Thara, a 25-year-old monk who was at the protest. "This kind of violence should not happen under a government that says it is committed to democratic reforms."