US forces, backed by Iraqi troops, kicked off an all-out offensive on Iraq's rebel-held city of Fallujah Monday evening. (Xinhua/Reuters photo) US soldiers battling in Fallujah, Nov. 9, 2004. (Xinhua/Reuters photo)

    BAGHDAD, Nov. 9 (Xinhuanet) -- Mortar bomb explosions were heard near the heavily fortified Green Zone compound in central Baghdad on Tuesday, witnesses said.

    They said four mortar rounds were launched as US helicopters were coming in to land in the vast compound that houses Iraqi government offices, US and British embassies.

    It was still unclear that any casualty was caused and there was no immediate comment from the US military.

    Insurgents frequently attack the Green Zone in central Baghdad with mortars, rockets and car bombs. Enditem