Moscow: Four people were killed and 15 others injured, four of them seriously, in a powerful scooter bomb explosion outside a police building in Russia's Dagestan region near Chechnya on July 17.

Two police personnel, a pregnant woman and a child were killed as the bomb, attached to a scooter parked at the entrance of the police building in Khasavyurt city, exploded at 10:00 hours (local time), ITAR TASS news agency said quoting Dagestan's Interior Minister Lt Gen A M Tagirov.

A police car near the scooter bomb was blown off 20 meters away under the impact of the explosion, which Tagirov described as an "act of terrorism".

A criminal case for terrorism was opened to investigate the explosion, he told TASS.

Dagestan, a mostly Muslim region in Southern Russia, is plagued by violence both related and unrelated to the fighting in the neighbouring Chechnya and Khasavyurt is in the Western part of Dagestan near the Chechen border.

PTI