The PNS Mehran attack was an attack/shooting by Tehrik-i-Taliban Pakistan (TTP) and Al Qaeda which took place on 22 May 2011, at PNS Mehran, the headquarters of the Pakistan Navy's Naval Air Arm and the most populous Pakistani military installation, located near the PAF's Faisal Air Force Base of Karachi, Sindh. In the course of the event, 15 attackers killed 18 military personnel and wounded 16 in a sophisticated terrorist attack which lasted 16 hours. Two American-built P-3C Orion surveillance aircraft were destroyed.