KABUL, Afghanistan (CNN) -- A senior al Qaeda leader in Afghanistan who escaped last year from Bagram prison has been captured, U.S. military sources said Monday. Abu Nasir al-Qahtani was among six people arrested last Monday during a raid by coalition and Afghan forces in Khost province, the sources said. A coalition military press release issued at the time of al-Qahtani's arrest described him only as a "known al Qaeda terrorist" and said he was taken into custody along with Saudi and Pakistani nationals. Al-Qahtani was one of four al Qaeda detainees who escaped from the high-security detention facility at...