Navy carried out a small-scale bombardment of the Indian coastal town and radar station of Dwarka, 200 miles (300 km) south of the Pakistani port of Karachi. Codenamed Operation Dwarka, it did not fulfill its primary objective of disabling the radar station. There was no significant Indian retaliation, since 75% of the Indian naval vessels were undergoing maintenance or refitting in the harbour. Some of the Indian fleet sailed from Bombay to Dwarka to patrol the area and deter further bombardment. Operation Dwarka has been described as an "insignificant bombardment" of the town was a "limited engagement, with no strategic value." Indo-Pakistani war of 1971 The Indian Navy played a significant role in the bombing of Karachi harbour in the 1971 war. On 4 December, it launched Operation Trident during which missile boats INS Nirghat and INS Nipat sunk the minesweeper and destroyer PNS Khyber. The destroyer PNS Shahjahan was irreparably damaged. Owing to its success, 4 December has been celebrated as Navy Day ever since. The operation was so successful that the Pakistani Navy raised a false alarm about sighting an Indian missile boat on 6 December. Pakistan Air Force (PAF) planes attacked the supposed Indian ship and damaged the vessel before it was identified as being another Pakistani Navy ship, PNS Zulfiqar which suffered numerous casualties and damage as a result of this friendly fire. During Operation Python on 8 December, the frigate PNS Dacca was severely damaged by INS Veer and the oil storage depot of Karachi was set ablaze. On the western front in the Arabian Sea, operations ceased after the Karachi port became unusable due to the sinking of Panamian vessel Gulf Star. An Indian frigate, INS Khukri was sunk by submarine PNS Hangor. On the eastern front, the submarine PNS Ghazi was sunk outside Vishakhapatnam harbour. Indian naval aircraft, Sea Hawks and Alizés, from the aircraft carrier were instrumental in sinking many gunboats and merchant navy vessels in the Bay of Bengal. The successful blockade of East Pakistan by the Indian Navy proved to be a vital factor in the Pakistani surrender. Operations after 1971 The Indian Armed Forces initiated Operation Cactus to prevent a coup attempt by a group of Maldivians led by Abdullah Luthufi and assisted by about 200 Sri Lankan Tamil mercenaries from the People's Liberation Organisation of Tamil Eelam (PLOTE) in Maldives in 1988. After Indian paratroopers landed at Hulhule