Thousands of demonstrators were marching in Yerevan late on July 25 in support of a group of gunmen who have occupied an Armenian police station for more than a week.

The demonstrators chanted “unity” and called for bystanders to join them -- swelling their numbers as the march progressed along the streets of the Armenian capital and the demonstrators arrived at Yerevan’s central Republic Square.

It was the largest gathering of support for the gunmen since the crisis began on July 17.

The march began on July 25 after military helicopters were seen flying over the occupied police building.

The presence of the helicopters prompted speculation that a military raid against the gunmen was imminent.

The gunmen at the police station set a police van on fire near the building on July 25.

Meanwhile, Armenian law enforcement agencies called on the gunmen not to take any steps that would "risk the lives of citizens or that stir up tensions."

One police officer was killed on July 17 when the gunmen, linked to the radical Founding Parliament opposition movement, stormed into the Erebuni police station.

The gunmen took seven police officers as hostages but released the last of them on July 23 after negotiations with a senior officer in Armenia’s armed forces.

The gunmen are members of a little-known group called Sasna Tsrer, dubbed by some the Daredevils of Sassoun, which is loyal to Founding Parliament’s leader Zhirayr Sefilian.

They say they have no intention of laying down their weapons until their demands are met.

Those demands include the resignation of President Serzh Sarkisian and the release of Sefilian, who was arrested along with six of his supporters on June 20 on illegal weapons charges.

Police initially accused Sefilian of preparing a plot to seize government buildings and telecommunication facilities in Yerevan.

Most of Sefilian’s supporters in Sasna Tsrer are veterans of the Nagorno-Karabakh conflict in the late 1980s and early 1990s.

Founding Parliament is sharply critical of the way Armenia’s government has dealt with the long-running conflict over Azerbaijan's breakaway region of Nagorno-Karabakh, a territory that both Armenia and Azerbaijan claim.