At least three people were killed in an explosion and shootout on Saturday in the centre of the Kazakh city of Taraz, Interfax news agency reported, the latest in a string of blasts in the usually peaceful central Asia state.

Interfax said the shootout and blast occurred outside the building of the National Security Committee in the city in southern Kazakhstan. It cited its correspondent at the scene as saying he had seen police removing a body in a black bag.

Quoting unspecified witnesses, RIA news agency also reported that three people had been killed in central Taraz. The agency reported that shooting had been heard and police helicopters were hovering over the city centre.

Police officials could not be immediately reached for comment.

A recent series of blasts in Kazakh cities has unnerved the authorities and public of the normally calm, predominantly Muslim former Soviet country of 16.6 million.

Last week a militant Islamist group claimed responsibility for two explosions in the western Kazakh oil city of Atyrau, after earlier threatening violence.

The oil-producing nation, which is Central Asia's largest and most successful economy, had until this year not witnessed outbursts of Islamist militancy seen in other parts of former Soviet Central Asia.

(Reporting by Dmitry Solovyov and Vladimir Soldatkin; Editing by Peter Graff)