(dpa) Intense clashes broke out Saturday between militants and joint US-Iraqi forces in Baghdad's Shiite al-Sadr city, witnesses told Deutsche Presse-Agentur dpa.
Gunshots had been heard in the district since late Friday and had lasted until early Saturday, witnesses added.
Separately, joint US-Iraqi troops backed by helicopters attacked the Hayaniya district of Basra, where most of radical Shiite cleric Moqtada al-Sadr's close aides are concentrated, witnesses said.
Loud explosions were heard in southern Iraq's second largest city while intense clashes occurred between militants and US-Iraqi forces.
Witnesses said the attacks had resulted in casualties, but reliable figures were not yet available.
Police and army troops have launched operations in the Hayaniya district in search of militants and criminal gangs with illegal weapons, Iraqi army sources told dpa.
On March 25, the Iraqi government launched a security operation in Basra codenamed "Charges of the Knights" aimed at militants and Moqtada al-Sadr's Mahdi Army fighters.