(Updates with detail) BAGHDAD, April 30 (Reuters) - Up to a dozen loud explosions rocked central Baghdad after nightfall on Monday and smoke was seen rising from the Green Zone government compound, Reuters witnesses said. The sound of sirens coming from the Green Zone could be heard across Baghdad after the blasts, which sounded like mortar bombs or rockets. The vast Green Zone complex houses the U.S. and British embassies as well as Iraqi government buildings. A U.S. military spokesman said he had no immediate information on the blasts. U.S. embassy officials could not be reached for comment. Insurgents often fire mortars or rockets at the Green Zone, but they rarely cause casualties. U.S. and Iraqi troops launched in February a major crackdown in the capital to rein in spiralling violence.
