Troops opened fire on pro-democracy protesters on Wednesday, killing at least 15 people and wounding dozens, activists and media said.
The dead include 46 children, according to the Assistance Association for Political Prisoners activist group, yet protesters are vowing to continue daily "guerrilla rallies."
At least 510 civilians had been killed in nearly two months of efforts to stop protests, an advocacy group said, while the death toll from Saturday alone had risen to 141.
Protests were held in Yangon and Mandalay, the country's two biggest cities, as well as elsewhere. Some of the demonstrations were again met with police force.