4th December is celebrated as “Navy day” by the Indian Navy to mark the operational success of the attack on Karachi port in 1971, the Indo-Pak war. The Indian Naval Headquarters in Delhi along with Western Naval Command planned to attack the port of Karachi by forming a strike group for the mission code-named “Operation Trident.”
Operation Trident was aimed to surprise and demoralize the Pakistan Navy, as the defense of Karachi port was paramount to Pakistan. The Karachi port city got the best defense Pakistan could offer; it also got a cover from strike aircraft-based airfield Masroor and Faisal Airbase of Pakistan military.
The strike group was based on Vidyut class missile boats. These boats had limited range, to overcome this difficulty support vessels including a refueling tanker were assigned to the group. These Vidyut class boats, INS Nipat, INS Nirghat, and INS Veer were armed with four SS-N-2B Styx Surface to surface missiles with a range 75km/ 40NM. On 4th December 1971, embarked on INS Nipat, Commander BB Yadav (CO 25th Squadron) led the strike group. These missile boats were escorted by two anti-submarine Arnala class Corvettes, INS Katchall and INS Kiltan, along with the fleet tanker INS Poshak.
Also read: Operation cactus Lily 1971
According to the operational plan, the missile boats were to attack at night because most of the PAF aircraft didn’t have night bombing capabilities. The task group reached 250 nautical miles/460 KM south of Karachi port and stayed in the area till sunset. In the evening of 4th December 1971, INS Kiltan and the three missile boats approached the port of Karachi by evading Pakistani reconnaissance patrol vessels and aircraft. At 2300 hours IST, the task group converged about 70 nautical miles south of Karachi port and detected Pakistani targets. INS Nirghat steered and engaged towards the northwest target, after verification, INS Nirghat fired an SS-N-2B Styx missile at the destroyer. PNS Khaibar, which was patrolling the shores, mistook the incoming missile as an aircraft and engaged with its anti-aircraft guns. The missile struck PNS Khaibar on the starboard side, Khaibar immediately lost propulsion and plunged into the darkness. In the panic, PNS Khaibar sent incorrect coordinates of the ship that resulted in delays in rescuing the survivors. The target (PNS Khaibar) was still afloat, INS Nirghat fired another missile towards PNS Khaibar, again the incoming missile was engaged by the anti-aircraft guns of the Khaibar. The missile struck Boiler no.2 and sank the PNS Khaibar.
At 2330 hours IST, INS Nipat engaged two targets approaching northeast of Karachi. INS Nipat verified and fired 1 Styx missile at the MV Venus Challenger and its destroyer escort PNS Shah Jahan. MV Venus Challenger was carrying ammunition for the Pakistan defense forces from the US forces. MV Challenger exploded as soon as the Styx missile struck it; PNS Shah Jahan too got heavily damaged. At 2350 hours, INS Veer fired a Styx missile at minesweeper PNS Muhafiz that got hit on the port side abaft the bridge that immediately the minesweeper before it could send a signal to PNHQ.
Furthermore, INS Nipat approached the Karachi port and fired two missiles at Kemari oil storage tanks of the port from 14nm south of the harbor. One missile missed the target, whereas the second missile hit the fuel tanks, instantaneously destroying the tanks and causing heavy loss to the port. The task force withdrew and came back to Indian territorial waters after completing the mission. This attack mission humiliated and destroyed the emotions of the Pakistan armed forces command and will be remembered in the history of Naval warfare.