MOSCOW, January 12 (RIA Novosti) - Representatives of the Mongolian opposition have taken over the Ulan Bator headquarters of the Mongolian People's Revolutionary Party (MPRP), one of the country's leading political parties, an MPRP activist said Thursday.

"Representatives of two public movements, Civil Will and For Drastic Reform, seized the headquarters of the MPRP and have been holding the building for more than three hours," said Dashdorzhin Zorigt, leader of the party's youth organization. About 2,000 people were in and around the building, Zorigt said.

The protests, which began in the city's main square, followed the MPRP's withdrawal Wednesday from the country's coalition government. MPRP members had occupied 10 of the seats in the government's 18-strong cabinet.

The MPRP members said they had withdrawn because they could no longer work with the Democratic Party, of which Tsakhia Elbegdorj, Mongolia's prime minister, is a member. Mongolian President Nambar Enkhbayar is the head of the MPRP.

The opposition was demanding Thursday that the country's parliament be dissolved and the decision to remove the government be revoked, Zorigt said.

A source in Ulan Bator said opposition leaders had established an interim people's council, which had decided not to give the building up until its demands were met.

The MPRP's secretary general is reported to have agreed to meet with opposition leaders. Law enforcement officials have refrained from using force.

The MPRP, which was formerly the country's communist party and which has formed most of Mongolia's governments since the move to democracy in 1990, holds 50% of the seats in the Great State Hural, the country's parliament.