BAGHDAD, January 28.— An estimated 100 to 250 people were killed on Sunday during fierce clashes in the outskirts of Nayaf, 150 km south of the Iraqi capital.

Resistance forces were still fighting on Sunday night against joint Iraqi and U.S. armed troops, according to sources with local security forces.

A U.S. helicopter that bombed the area was shot down and its two occupants killed.

Lieutenant Colonel Ali Yeriou, spokesman for the Iraqi armed forces, told state television that about 100 armed rebels were killed in combat, without specifying how many casualties there were among Iraqi and U.S. soldiers.

According to the Iraqi news agency Aswat al Iraq the joint troops received support form U.S. planes and tanks that bombed the Zarqa neighborhood, where "hundreds of rebels" had taken refuge, according to the EFE.

The AP reported that at least five girls were killed and 20 more injured on Sunday after a mortar attack on a girls’ school in the Sunni area of Baghdad.

Meanwhile, the EFE reported that at least six U.S. soldiers had died and another six were wounded over the last three days in various attacks by the insurgency.