Seven gunmen and six policemen were killed in a battle in the Chechen capital Grozny on Thursday, Dec 4, the leader of the turbulent southern Russian region said.

Chechnya's Kremlin-backed Ramzan Kadyrov, said that "the terrorists were annihilated" after they opened fire at a police patrol car, killing officers, and then stormed offices housing local media.

According to RT, Kadyrov said the attackers dressed in police uniforms assaulted the officers.

"Dressed in police uniforms, they made their way and killed innocent boys who were on duty at this post. They will not escape retribution," Kadyrov said in a Chechen-language Istagram video.

Muslim separatists in Chechnya have fought two wars with Russian forces since the break-up of the Soviet Union in 1991. Grozny has been relatively calm in recent years, following a security crackdown under Kadyrov. However, in October a suicide bomb attack in the Chechen capital killed five police officers and left at least 12 people injured.