Defence Day is celebrated in Pakistan as national day to commemorate the sacrifices made by Pakistani soldiers in defending its borders on 1965 war with India. The date of 6 September marks the day in 1965 when 7,000–8,000 Indian troops and more than 500 tanks crossed the international border to launch an attack on Punjab, Pakistan. In the second stage, on 1 September, it launched a tank attack, dubbed Operation Grand Slam, towards the Akhnoor bridge in the Jammu Division. While it is officially commemorated as an unprovoked surprise attack by India, which was repulsed by the Pakistan Army despite its smaller size and fewer armaments.