Baghdad: Iraqi police arrested dozens of members of Shiite cleric Moqtada Al Sadr's Mehdi Army militia on Saturday, hours after two policemen were killed in gunbattles in the southern city of Kut, police said.

Lieutenant Aziz Al Amara, who commands a rapid reaction unit, said, "This operation started in the early morning and so far we have arrested 25 wanted people from the Mehdi Army."

Another police official, who declined to be named, said 70 people had been detained. Police say at least 13 people have been killed in fighting since Tuesday.

Clashes this week between Iraqi security forces and the militia in Kut, southeast of Baghdad, have raised fears that a ceasefire called by Sadr may unravel, although the violence has so far been confined to Kut.

It is the first major violation of the seven-month-old truce, which has been credited by the US military with helping to reduce violence between majority Shiite and Sunni Muslims that has killed tens of thousands of Iraqis.