On 4 December, the fleet successfully executed Operation Trident, a devastating attack on the Pakistan Naval Headquarters at Karachi that sank a minesweeper, a destroyer and an ammunition supply ship. The attack also irreparably damaged another destroyer and oil storage tanks at the Karachi port. To commemorate this, 4 December is celebrated as the Navy Day. This was followed by Operation Python on 8 December 1971, further deprecating the Pakistan Navy's capabilities.