BAGHDAD, Jan 23 (Reuters) - U.S. and Iraqi troops backed by helicopters clashed with gunmen in central Baghdad on Tuesday and two residents said a helicopter appeared to have made an emergency landing after being shot. A police source also said they had reports of a helicopter coming down in the area but it was not clear whether it belonged to the U.S. military or a private security firm. A U.S. military spokesman said he was checking the report but had no information yet. The clashes took place on the east bank of the Tigris river in the centre of old Baghdad. A reporter working for Reuters said up to around 50 military vehicles were in the area, backed by several helicopters, and there was sustained gunfire. Earlier this month U.S. and Iraqi forces launched a major assault on the opposite side of the river in the Haifa Street area to root out Sunni Arab insurgents, killing more than 100.
