(adds comment from Iraqi official) BAGHDAD, Feb 24 (Reuters) - More than 20 loud explosions in quick succession rocked southern Baghdad on Saturday evening, Reuters witnesses said. "The cause of the explosions ... earlier came from indirect fire landing into the red zone. At the moment we do not know where it is coming from," the U.S. military said in a statement, referring to the area outside the international Green Zone where most U.S. officials and Iraqi government offices are based. Indirect fire is a term used by the U.S. military for mortar rounds, rockets and artillery. U.S. and Iraqi troops are conducting a large-scale security crackdown in Baghdad aimed at stemming sectarian bloodshed that threatens to plunge the country into civil war. Brigadier Qassim Moussawi, spokesman for Iraqi forces conducting the security plan, told Reuters the blasts were linked to military operations. "The explosions are a result of military operations by Iraqi and multinational forces against terrorist hideouts," he said. Mortar attacks are a daily occurrence in the city, particularly since Shi'ites and Sunni Arabs have become increasingly divided into sectarian enclaves. However, it is rare for so many explosions to be heard close together.
