Riot police in the Armenian capital, Yerevan, have clashed with supporters of an armed group barricaded with hostages inside a police station.
Dozens of protesters were hurt. Three gunmen were wounded in earlier clashes.
The group stormed the building nearly two weeks ago seeking the release of "political prisoners" including opposition leader Jirair Sefilian.
Mr Sefilian has strongly criticised President Serge Sarkisian's handling of the Nagorno-Karabakh conflict.
Police with truncheons and stun grenades charged at protesters shouting "Free independent Armenia" and "Serge, leave!".
Sputnik Armenia news agency said as many as 60 people had been injured in the riots and about 40 were still being treated in hospital.
Radio Liberty said three of its journalists were among the injured and that a camera was smashed.
More than 100 people were reportedly detained by police.
The three gunmen who were wounded sustained their injuries in a shootout earlier on Friday.
They were apparently shot in the legs by snipers. Two of them were escorted to hospital under armed guard.
The group seized the police station on 17 July, killing one policeman and taking several hostages. Some of the captives have since been freed.
They released a video demanding the release of Mr Sefilian and a number of others, and urging supporters on to the streets.
The CivilNet newspaper identified the group as the Daredevils of Sassoun.
The group has been quoted as saying it will retaliate if attacked and has no intention of surrendering.
Mr Sefilian, a former military commander, has criticised the government's handling of the long-running conflict involving pro-Armenian separatists in the region of Nagorno-Karabakh.
Nagorno-Karabakh lies within Azerbaijan but has an ethnic Armenian majority. A bloody war erupted after the end of Soviet rule in 1988, and there has been frequent unrest since, the latest in April, when clashes left dozens dead.
