BAGHDAD, Feb. 2 (Xinhua) -- The U.S. military said they were checking reports of a possible aircraft down on Friday, while witnesses said two helicopters were hit in north of Baghdad.

    Earlier, media reports quoted residents from the nearby area of Taji, some 20 km north of Baghdad, as saying that they saw helicopter come down shortly after dawn.

    The U.S. military did not confirm the incident, only saying they were checking reports of a possible aircraft down.

    However, a witness from the Salman village near the Mashahda town, about 20 km north of Baghdad, told Xinhua that he saw gunmen opened fire on two helicopters flying above the area at about 7:30 a.m. (0430 GMT).

    "One Apache helicopter was shot down, of which later I saw wreckage near warehouses in the area, while the other one caught fire but I didn't see it crash because it was far away from my place," the witness said on condition of anonymity.

    There is a large U.S. military airbase located near the area. During the past two weeks, three U.S. helicopters have crashed in Iraq.

    On Sunday, a U.S. military helicopter crashed in a combat operation near southern Iraqi city of Najaf, killing two U.S. soldiers aboard.

    On Jan. 23, a U.S. helicopter belonging to a private security company was shot down in central Baghdad and the five people aboard were killed.

    On Jan. 20, a U.S. force Blackhawk helicopter went down northeast of Baghdad, killing 12 people abroad.