A suicide bomber has blown himself up outside a hall where thousands were gathering for a concert to mark Grozny City Day.
Five police officers are dead and 12 injured after they "foiled an attempt" by a suicide bomber to attack a concert hall in the capital of Chechnya.
The attacker blew himself up outside the hall where thousands were gathering for a concert to mark Grozny City Day in the regional capital, an interior ministry spokesman said on Sunday.
He triggered the explosives after police securing the venue tried to inspect the man's identity papers, the spokesman added.
The Russian Investigative Committee identified the bombing suspect as a 19-year-old named Opti Mudarov.
"Five police were killed and 12 others were injured," it said in a statement.
The bombing took place several hours before the scheduled start of the concert, which also coincided with the birthday of strongman regional president, Ramzan Kadyrov.
"At the cost of their lives, the police saved the lives of thousands of people," said Russian Interior Minister Vladimir Kolokoltsev, quoted by state news agency TASS.
Kadyrov said the bomber "wanted to ruin people's joy on their day of celebration, but he has not succeeded," according to the news agency Ria Novosti.
Following a failed uprising against the Russian government in 1994-1996, the Chechen separatist movement became increasingly radical, evolving into a violent Islamist insurgency in the 2000s.