On 4 December 1971, the aircraft carrier
Vikrant was also deployed and its
Hawker Sea Hawk attack aircraft contributed to
Air Operations in East Pakistan. The aircraft successfully attacked many coastal towns in East Pakistan including Chittagong and
Cox's Bazar. The continuous attacks later destroyed the PAF's capability to retaliate. The
Pakistan Navy responded by deploying her ageing long-range submarine, PNS
Ghazi, to counter the threat as the Naval Command had overruled the objections by her officers.
Ghazi, under the command of Commander
Zafar Muhammad Khan, was assigned to locate
Vikrant, but when it was not able to locate, decided to mine the port of
Visakhapatnam – the headquarters of Eastern Naval Command. The Indian Navy's Naval Intelligence laid a trap to sink the submarine by giving fake reports about the aircraft carrier. At around midnight of 3–4 December,
Ghazi began its operation of laying mines. The Indian Navy dispatched to counter the threat.
Rajputs sonar radar reported the disturbance underwater and two depth charges were released. The deadly game ended when the submarine sank mysteriously while laying a mine with all 92 hands on board around midnight on 3 December 1971 off the Visakhapatnam coast.The
sinking of
Ghazi turned out to be a major blow and setback for Pakistani naval operations in East Pakistan. On 5/6 December 1971, naval air operations were carried out Chittagong, Khulna, and Mangla harbours, and at ships in the Pussur river. The oil installations were destroyed at Chittagong, and the Greek merchant ship
Thetic Charlie was sunk at the outer anchorage. On 7/8 December, the airfields of PAF were destroyed, and the campaign continued until 9 December. On 12 December, Pakistan Navy laid
naval mines on amphibious landing approaches to Chittagong. This proved a useful trap for some time, and it had denied any direct access to Chittagong port for a long time, even after the instrument of surrender had been signed. The Indian Navy therefore decided to carry out an amphibious landing at
Cox's Bazar with the aim cutting off the line of retreat for Pakistan Army troops. On 12 December, an additional amphibious battalion was aboard was sailed from Calcutta port. On the night of 15/16 December, the amphibious landing was carried out, immediately after IAF bombardment of the beach a day earlier. After fighting for days, the human cost was very high for Pakistani forces, and no opposition or resistance was offered by Pakistani forces to Indian forces. During this episode Eastern theatre Indian forces suffered only 2 deaths in the operation. Meanwhile, Pakistani forces were reported to have suffered hundreds of deaths. By the dawn of 17 December, the Indian Navy was free to operate at will in the Bay of Bengal.
Elimination of gunboat threats Indian carrier-borne aircraft attacked the
Rajshahi and
Comilla near Chittagong on 4 December, with the
Rajshahi damaged and the
Comilla sunk. The survivors later were evacuated by ships and helicopters operating at night. PNS
Rajshahi was repaired, and under the command of Lt. Commander Sikander Hayat, managed to evade the Indian blockade and reach Malaysia before the surrender on 16 December. From there, it sailed to Karachi and continued to serve in the Pakistan navy. ==Sinking of INS
Khukri==