A suicide bomber has killed five police officers and injured several more in a reported attempt to attack a concert hall in the Russian region of Chechnya.
The attack happened outside of a concert hall in the capital Grozny on Sunday, as thousands of people were gathering in advance of celebrations for a local holiday.
Local officials said the bomber killed five policemen and wounded 12 others as the city celebrated the birthday of Chechnya's pro-Kremlin leader Ramzan Kadyrov.
The Investigative Committee, Russia's leading federal investigative agency, also said that five policemen were killed and 12 others wounded. No civilians were reported injured in the attack.
The attacker was believed to be a 19-year-old resident of Chechnya, the agency said in a statement.
The bomber triggered the explosives after police tried to inspect the man's identity papers, a Russian Interior Ministry said.
"Police officers who were manning metal detectors at the entrance of the concert hall noticed a suspicious young man. When the police officers decided to check the individual, the man blew himself up," a local police officer told the RIA news agency.
Al Jazeera cannot independently verify the authenticity of the official version of the incident.
The Tri-City Herald daily newspaper quoted Kadyrov as saying that the suicide bomber was wearing a police uniform and presented police identification when he tried to go through metal detectors set up outside the concert hall.
When police moved to stop him, he detonated the explosives, Kadyrov said.
Several ambulances were seen leaving the site, which was blocked off by police.