Eight people, seven of them police, were killed in a suicide attack in Chechnya's capital Grozny on Tuesday during celebrations at the end of the Muslim festival of Ramadan, a police source told Interfax news agency.
A man detonated an explosive device when a police patrol tried to detain him and a second blast rang out soon afterwards, an unidentified police official told the privately-owned agency.
The explosion killed seven police officers, an emergency services worker and wounded at least 16 people, Interfax added.
The scene of the explosion, in a densely populated district of Grozny 50 metres from a local parliament building, was cordoned off by the police. Residents told Reuters they heard gun shots after the explosions.
A decade after Russian forces drove separatists out of power in Chechnya, the Kremlin is still struggling to contain an Islamist insurgency in the north Caucasus. The violence has now spread from Chechnya to other mainly Muslim regions.
None of the Islamist rebel leaders claimed responsibility for the attack.
"Today is the most sacred day for all Muslims. On that day a trained and zombified bandit attempted to carry out a terrorist attack," Chechnya's Moscow-backed leader Ramzan Kadyrov told RIA news agency.
"The bandits have shown their real face which only proves that this evil should be eradicated," Kadyrov added. (Writing by Gleb Bryanski; Editing by Andrew Heavens)