KABUL, July 11 (Xinhuanet) -- Four suspected al-Qaida operatives have escaped the most fortified US detention center at US military Headquarters in Afghanistan, a US army statement said Monday.

    "Four detainees were reported missing at approximately 5 a.m. and search operations began shortly thereafter," the statement issued in the afternoon said.

    It did not give more details. However, Afghan sources say that all the escaped inmates were Arabs affiliated with al-Qaida network.

    "Four detainees in the Bagram Airfield detainment facility are unaccounted for, prompting an extensive search," it said.

    This is the first time that detainees were able to escape US detention center and put on display security lapse in US holding facilities in Afghanistan.

    Local government officials and ground units backed by US military helicopters, the statement added, were searching the surrounding areas to recapture the escaped detainees.

    "An investigation into the incident is going on," concluded thestatement. More than 400 suspected Taliban and al-Qaida operatives have been held in 23 US military detention centers in Afghanistan.Enditem