At least 42 people have been killed in fighting in the mountainous region of Pamir in Tajikistan.
Unconfirmed reports say the level of casualties is far higher and that hundreds of people have been killed.
The fighting erupted after a senior security official was found stabbed to death on Saturday.
That led to military action being taken against Tolib Ayombekov, who fought against the government during a civil war in Tajikistan after the country became independent from the Soviet Union in 1991.
Security forces say they decided to use force after Mr Ayombekov refused to surrender.
State television said that police detained 40 armed men on Tuesday. It said 23 soldiers were injured in an operation in Khorog, the provincial capital - but there were no civilian casualties.
Residents have told the BBC their town now resembles a warzone. People are trapped in their homes because of heavy fighting in the streets, where armoured vehicles have been seen.
Communications in Gorno-Badakhshan province have since been cut.