Gronzy, July 26 (RIA Novosti) Three police officers were killed Sunday in a suicide blast in this capital of Russia's Chechnya republic, a police source said.

'According to preliminary information, an explosive device was set off by a suicide bomber. Law enforcement officials are working at the scene,' the source told RIA Novosti.

The number of wounded has not yet been reported.

The last terrorist attack to hit the North Caucasus republic was July 7, when a bomb went off in a trash can, injuring nine people.