Four Americans, two service members and two contractors, were killed when a man detonated his suicide vest early Saturday morning at Bagram Airfield in Afghanistan. NBC News reports that an additional 16 American service members were injured in the blast, as well as one coalition soldier from Poland, and notes that the bomber struck as people were gathering for a post–Veterans Day fun-run. The Taliban has since claimed responsibility for the bombing, which it said it had been planning for four months. The base, which is the largest U.S./NATO facility in Afghanistan, was put on lockdown following the attack. The identities of the victims have not been released.
It is not clear how the bomber was able to bypass the base’s multiple layers of security, but an Afghan official who spoke with the Associated Press said that laborers who work at the base typically line up to enter the gates around the time the attack took place, and the bomber may have hidden among them.