Armenian security forces gave armed members of a radical opposition group until 5 p.m. Saturday to lay down their arms or face a large-scale assault on a police station in Yerevan that has been occupied by them for the past two weeks.

“Or else, special units of law-enforcement bodies will be authorized to open fire and neutralize, without prior warnings, any armed person in and outside the [seized] police regiment,” Armenia’s National Security Service (NSS) said in a statement issued at 4 p.m. local time.

The NSS linked the ultimatum with intensive gunfire which it said the gunmen opened late on Friday at NSS and police units surrounding them. It said a number of police officers was wounded before the security forces returned fire.

“After what happened on the evening of July 29, all real possibilities of reaching a peaceful resolution of the situation with the terrorists have been exhausted,” declared the security agency. Use of force against them has become “absolutely necessary” in these circumstances, it added.

The NSS specifically stressed the need to free two medics that are being held hostage by the armed oppositionists. Another doctor taken captive by them on Wednesday reportedly escorted two wounded gunmen to hospital overnight and thus regained his freedom.

The sound of gunshots and explosion coming from the police compound in Yerevan’s Erebuni could be heard on Friday night as scores of protesters sympathetic to the gunmen rallied and clashed with riot police on nearby streets. At least one police officer is known to have been hospitalized with gunshot wounds afterwards.

The gunmen affiliated with Founding Parliament, a fringe opposition group, did not react to the ultimatum by the time it expired at 5 p.m. About a dozen members of the armed group have been wounded or captured by security forces in recent days.

The gunmen are thought to have numbered roughly 30 when they stormed the Erebuni police compound on July 17, killing one police officer and wounding several others. They demanded the release of Founding Parliament’s jailed leader, Zhirayr Sefilian, and President Serzh Sarkisian’s resignation.

Sarkisian has told the gunmen through mediators that he is ready to meet with Sefilian and discuss important issues with him only if they agree to surrender to law-enforcement agencies. The gunmen’s leader, Varuzhan Avetisian, has repeatedly rejected that demand.

Earlier on Saturday, Sefilian issued a statement from his prison, insisting that he be allowed to meet the gunmen before negotiating with the president on a possible compromise settlement. HE said Sarkisian continues to reject his offer.

The Lebanese-born oppositionist also condemned the authorities’ actions against the gunmen and their supporters and said Sarkisian is bearing full responsibility for the continuing dramatic events in Armenia.