Burundi's state radio has reported that more than thirty people have been killed and about twenty wounded in an overnight attack south of the capital, Bujumbura.

The killings happened in the Nyamaboko and Kanyosha neighbourhoods and the radio blamed armed criminal gangs -- the official term for Hutu rebels.

Survivors told the BBC they were targeted because the rebels suspected them of collaborating with the government.

Correspondents say it's the first major incident since a third round of talks earlier this month aimed at ending the civil war.