KABUL, May 13 (Xinhua) -- A helicopter belonging to the U.S.-led Coalition forces has made an overnight hard landing in eastern Afghanistan, a Coalition statement said Tuesday.

    There were no injuries reported in the emergency landing which was made Monday night in Nuristan province bordering Pakistan, the U.S.-led military said.

    The cause of the hard landing has been unknown yet and the incident is under investigation, it said, adding that the helicopter has been transported to a Coalition base.

    The United States is leading a 20,000-strong multi-national force in Afghanistan, the majority of which is deployed in restive eastern regions.