Democracy activists freshly tested the new Myanmar government's avowed tolerance for dissent by gathering peacefully Monday at a central landmark in the country's biggest city in honor of giant protests four years ago.

Four truckloads of riot police and two prison vans stood nearby but police did nothing to interfere with almost 60 activists who held a prayer vigil at Sule pagoda in Yangon. However, police harassed or stopped marchers in other parts of the city.

A nominally civilian but army-backed government that took power earlier this year from a decades-long ruling junta has said it will liberalize politics, but it still continues to hold about 2,000 political prisoners.

The demonstrators at Sule pagoda said they were marking the September 2006 crackdown on protests led by Buddhist monks that brought as many as 100,000 people onto the streets of Yangon until the army quashed them with deadly force. Several dozen people were believed killed and thousands jailed.

"We are holding this peaceful expression of our wishes in accordance with the Constitution. We are exercising our rights," said Han Win Aung, one of the organizers, vowing to hold similar activities on the 26th of every month to let the people's voice be heard.

For the first time in recent memory, both the marchers and journalists openly photographing and filming them were left unmolested by police.

Monday's protesters called for freeing political prisoners and stopping construction of a dam on the Irrawaddy River they say is environmentally and socially deleterious.

In small but growing numbers, dissidents have staged protests after power was handed to a civilian government, despite skepticism the new regime is sincere about bringing about democratic change.

In northern Yangon, authorities stopped some 100 activists who sought to join the group on Sule pagoda, but made no arrests when some sought to continue their march.