Officer death used to ambush police in south Russia's Daghestan

MOSCOW, December 3 (RIA Novosti) - Four police officers were injured in a powerful explosion as they attended to a fellow officer who had been shot in Makhachkala, Daghestan's capital, a police source said on Wednesday.

The blast, the equivalent of 6 kg of TNT, occurred on Tuesday evening in the Kirov district in Russia's North Caucasus republic of Daghestan, when officers were called to investigate the death of a police inspector.

The officer, who later died in hospital, was shot by unknown gunmen as he left work.

"Twenty minutes after their arrival at the incident scene an explosive device was detonated near their police vehicle...Four police officers were injured and hospitalized," the source said.

A criminal investigation is underway.