Tajikistan authorities have opened an investigation into a high-ranking police official who allegedly has joined the Islamic State group in Syria and is calling for former comrades to rise up against the Central Asian country's authoritarian leadership.

News reports say Gulmurod Khalimov, who had commanded the country's OMON special police troops, made the claim in a video. The full video is no longer online, but an edited version shows Khalimov speaking from an undisclosed location accompanied by men in characteristic insurgent garb, and cradling a sniper rifle.

He challenges Tajik servicemen, saying: "Are you ready to die for this state?"

Tajik Prosecutor-General Manuchehr Makhmudzod announced the investigation Friday.

The former Soviet republic was devastated by a 1990s civil war with rebels that included Islamists.