On 4 December, the Indian Navy launched a fast naval strike on the Pakistan Naval Headquarters (PNHQ) of Karachi.
[14] The task group for the operation consisted of three
Vidyut class missile boats,
INS Nipat (K86),
INS Nirghat (K89) and
INS Veer (K82) from the 25th "Killer" Missile Boat Squadron, escorted by two anti-submarine
Arnala class corvettes,
INS Kiltan (P79) and
INS Katchall (P81), and a fleet tanker, INS
Poshak.
[6][14] The task group was led by the Commanding Officer of the 25th Squadron,
Commander Babru Bhan Yadav, embarked on INS
Nipat.
As per the operational plan, the task group reached 250 nautical miles (460 km) south of Karachi and stayed in the area during the day, outside the range of Pakistan Air Force (PAF) aircraft. The plan was to attack Karachi at night because most PAF aircraft did not possess night-time bombing capability.
[15] In the evening on 4 December,
Kiltan and the 3 missile boats approached Karachi, evading Pakistani reconnaissance aircraft and surface patrol vessels.
At 2230 hrs
PST, the task group converged about 70 nautical miles (130 km) south of
Karachi detected Pakistani targets, analysed as warships 45 miles to the northwest and 42 miles to the northeast.
Nirghat then steered towards and engaged the northwesterly target and after verification, fired the first
SS-N-2B Styx missile at the
destroyer,
PNS Khaibar, which was on patrol.
Khaibar mistook the missile to be an aircraft and engaged it with its Bofors anti-aircraft guns. The missile struck
Khaibar on the starboard side and exploded below the aft galley in the Electrician's mess deck at about 2245 hrs PST. The ship immediately lost propulsion, plunged into darkness and the No.1 Boiler room exploded, engulfing the ship in thick black smoke.
Khaibar sent out an emergency transmission to PNHQ which read "
Enemy aircraft attacked in position 020 FF 20. No 1 Boiler hit. Ship stopped." In the panic of the attack, the transmission sent incorrect coordinates of the ship's position, which resulted in delays in rescuing the survivors later. With the target still afloat, at about 2249 hrs,
INS Nirghat fired a second missile, which was seen approaching and again engaged with anti-aircraft guns of
Khaibar. The missile struck the No.2 Boiler room on the starboard side, sinking
Khaibar.
[10]
At 2300 hours,
Nipat engaged two targets to the northeast approaching Karachi. Verifying the targets,
Nipat launched 1 Styx missile each at the MV
Venus Challenger and her destroyer escort
PNS Shah Jahan (DD-962).
[9][10] India has claimed
[10][16][17] that the MV
Venus Challenger was carrying ammunition for Pakistan from the United States forces in
Saigon. The ammunition on the
Venus Challenger immediately exploded as the missile struck sinking her about 26 miles south of Karachi.
[16] The other missile hit PNS
Shah Jahan which was badly damaged and scrapped.
[7][8][10]
At 2320 hours, the
minesweeper PNS Muhafiz, was targeted by a Styx missile from
Veer. The missile hit
Muhafiz on the port side abaft the bridge, instantaneously disintegrating the vessel before it could send a transmission to the PNHQ.
Then we will blame it on Israel or Iran. 
