Iraq sent an armoured army division and a police strike force into the southern oil city of Basra to disarm residents amid intensified feuding between rival Shia Muslim tribes, a local official and three security sources said on Friday.

"This security operation targets areas north of Basra that have an abundance of tribal clashes and will also include neighbourhoods inside Basra city in the future," said Jabar al-Saadi, head of the security committee at the Basra provincial council.

The majority of crude exports from major OPEC oil producer Iraq come from southern oil fields around Basra.