A suicide bomber detonated explosives during holiday festivities coinciding with the birthday of Chechen leader Ramzan Kadyrov in Grozny, Chechnya, Sunday, Russian news agencies reported. The bombing killed five policemen and left 12 others injuried.

The festivities took place at a concert hall in the capital. Kadyrov, who witnessed the bombing, said the attacker was dressed in a police uniform and presented police identification.

"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 Novosti news agency.

The Investigative Committee, Russia's leading federal investigative agency, said no civilians were killed or injured in the blast.

The bomber was reportedly a 19-year-old Grozny native, who went missing from his home two months prior to the bombing, police said. Chechnya has experienced two separatist wars in 1994-96 and 1999-2000. While  the republic has stabilized during Kadyrov’s rule, Islamic insurgency remains an issue. In 2013, a suicide bombing struck Volgograd, a city north of the volatile Caucasus region, which experiences regular unrest from Islamic insurgency. A train station and an electric trolleybus were bombed, leaving 34 people dead, prompting heightened security at the 2014 Winter Olympics in neighboring Sochi.

The attack may have been specifically targeted at Kadyrov. The leader said he has been peronally threatened by an insurgent group called the Caucasus Emirate in the past.