A suicide bomber exploded their vehicle at the entrance of a U.S. military base in Afghanistant on Wednesday, the AP reports, killing the attacker and three Afghans:

Police Gen. Abdul Qayum Baqizai said a local guard who questioned the vehicle driver at the gate of Camp Chapman was killed along with two civilians and the assailant. The camp is located adjacent to the airport of the capital of Khost province, which borders Pakistan. Chapman and nearby Camp Salerno had been frequently targeted by militants in the past, but violent incidents have decreased considerably in recent months.

Taliban spokesman Zabihullah Mujahid said in an email that the bomber targeted Afghan police manning the gate and Afghans working for the Americans entering the base. He claimed high casualties were inflicted.