Thousands of Maoist supporters swarmed into Nepal's capital Saturday for a May Day rally that was also intended to press the government to step down.
About 15,000 security forces were deployed throughout the capital and businesses were shut in anticipation of violence, but by midday the situation was still peaceful.
Police estimated 100,000 people had shown up for the rally. The Maoists said they expect to have about 500,000 supporters.
Protesters are demanding that the prime minister step down and that the Maoists be able to lead the government again.
The protests come during a difficult political phase in Nepal, with the deadline to draft the constitution coming at the end of the month.
The Maoists have threatened an indefinite general strike starting Sunday if Prime Minister Madhav Kumar Nepal does not resign by Saturday evening.