At least 5,000 protesters have massed in Armenia's capital, Yerevan, to push for early elections.

The opposition Armenian National Congress, led by former President Levon Ter-Petrosian, organized Friday's rally in the city. During the rally, the protesters also promised more demonstrations unless their demands are met, including the release of an opposition activist arrested last month following a clash with police.

Yerevan has been the scene of protests against the government of President Serzh Sarkisyan since the 2008 election, which the opposition has called fraudulent. In addition to demanding early elections, the demonstrators have called for the release of political prisoners.

A dialogue between the opposition and authorities began recently but was suspended after the activist's arrest.

Rights groups and the opposition have accused Mr. Sarkisyan and his government of ordering politically motivated trials in response to deadly political unrest that occurred following his disputed 2008 victory. Opposition members claimed the vote was rigged. They also accuse authorities of failing to investigate widespread accusations that police used excessive force to crush the protests.

Last February, the parties making up the government's ruling coalition showed their support for Mr. Sarkisyan when they signed a memorandum supporting his election to a second term in 2013.