- In 1971, the Port of Karachi housed the headquarters of the Pakistan Navy and almost its entire fleet was based in Karachi Harbour.
- Since Karachi was also the hub of Pakistan’s maritime trade, a blockade would be disastrous for Pakistan’s economy. The security of Karachi Harbour was predominant to the Pakistani High Command and it was heavily defended against any air or naval strikes.
- Towards the end of 1971, there were rising tensions between India and Pakistan, and after Pakistan declared a national emergency on 23 November, the Indian Navy deployed three Vidyut-class missile boats in the vicinity of Okha, near Karachi, to carry out patrols.
- On 3 December, after Pakistan attacked Indian airfields along the border, the Indo-Pakistani War of 1971 officially began
- The Indian Naval Headquarters (NHQ) in Delhi, along with the Western Naval Command, planned to attack the Port of Karachi.
- This strike group was to be based around the three Vidyut-class missile boats already deployed off the coast of Okha. However, these boats had limited operational and radar range and to overcome this difficulty, it was decided to assign support vessels to the group.
- On 4 December, what was now designated as the Karachi Strike Group was formed and consisted of the three Vidyut-class missile boats: INS Nipat, INS Nirghat and INS Veer.
- As planned, on 4 December, the strike group reached 250 nautical miles south off the coast of Karachi.
- As Pakistani aircraft did not possess night-bombing capabilities, it was planned that the attack would take place between dusk and dawn.
- INS Nirghat drove forward in a northwesterly direction and fired its first Styx missile at PNS Khaibar.The missile hit the right side of the ship, exploding below the galley in the electrician’s mess deck at 10.45 pm (PKT).
- Due to the chaos created by the explosion, the signal contained the wrong coordinates of the ship’s position.
- After verifying two targets in the area northwest of Karachi, at 11.00 pm (PKT), INS Nipat fired two Styx missiles – one each at cargo vessel MV Venus Challenger and its escort PNS Shah Jahan, a C-class destroyer.
- At 11.20 pm (PKT), PNS Muhafiz, an Adjutant-class minesweeper, was targeted by INS Veer. A missile was fired and Muhafiz was struck on the left side, behind the bridge. It sank immediately before it could send a signal to the PNHQ, killing 33 sailors.
- Soon the PNHQ deployed rescue teams on patrol vessels to recover the survivors of Khaibar. As Muhafiz sank before it could transmit a distress call
- The Pakistan Air Force retaliated for these attacks by bombing Okha harbour, scoring direct hits on fuelling facilities for missile boats, an ammunition dump, and the missile boats’ jetty.The Indian Navy anticipated this attack and had already moved the missile boats to other locations to prevent any losses.
- However, the destruction of a special fuel tank prevented any further incursions until Operation Python, executed three days later.
- With no casualties on the Indian side, this operation was considered to be one of the most successful in modern naval history post-World War II. To mark this victory, the Indian Navy annually celebrates Navy Day on 4 December
- A number of Indian Navy personnel were honoured with gallantry awards for the operation.
- Then Fleet Operations Officer, Captain (later Vice Admiral) Gulab Mohanlal Hiranandani, was awarded the Nau Sena Medal for the detailed operational planning.
- Maha Vir Chakra was awarded to the strike group commander, Yadav, for planning and leading the task force; and Vir Chakra were awarded to Lieutenant Commanders Bahadur Nariman Kavina, Inderjit Sharma, and Om Prakash Mehta, the commanding officers of INS Nipat, INS Nirghat, and INS Veer respectively. Master Chief M. N. Sangal of INS Nirghat was also awarded the Vir Chakra