On 1 September 1965, Pakistan launched a counterattack, called Operation Grand Slam, with the objective to capture the vital town of Akhnoor in Jammu, which would sever communications and cut off supply routes to Indian troops. Ayub Khan calculated that "Hindu morale would not stand more than a couple of hard blows at the right time and place" although by this time Operation Gibraltar had failed and India had captured the Haji Pir Pass. At 03:30 on 1 September 1965, the entire Chhamb area came under massive artillery bombardment. Pakistan had launched operation Grand Slam and India's Army Headquarter was taken by surprise. Attacking with an overwhelming ratio of troops and technically superior tanks, Pakistan made gains against Indian forces, who were caught unprepared and suffered heavy losses. India responded by calling in its air force to blunt the Pakistani attack. The next day, Pakistan retaliated, its air force attacked Indian forces and air bases in both Kashmir and Punjab. India's decision to open up the theatre of attack into Pakistani Punjab forced the Pakistani army to relocate troops engaged in the operation to defend Punjab. Operation Grand Slam therefore failed, as the Pakistan Army was unable to capture Akhnoor; it became one of the turning points in the war when India decided to relieve pressure on its troops in Kashmir by attacking Pakistan further south. In the valley, another area of strategic importance was Kargil. Kargil town was in Indian hands but Pakistan occupied high ground overlooking Kargil and Srinagar-Leh road. However, after the launch of a massive anti-infiltration operation by the Indian army, the Pakistani infiltrators were forced out of that area in the month of August.