NSG commandos keep a watch on Nariman House in Colaba on Thursday. (PTI)

New Delhi, Nov. 27: The army, navy and the air force have been forced to deploy resources in Mumbai in a way they never had to on internal security duty, a secondary task for them.

Such a tri-service military operation has been necessitated by a gang of suspected fidayeens, estimated to number between 10 and 30. The hostage situations in two five-star hotels and in a Colaba house have thrown up befuddling questions on what the terrorists are demanding, whether there is negotiation and how high is the risk of collateral damage.

Air force and naval helicopters, marine commandos, the army and the elite National Security Guard (NSG), which draws its personnel from the armed and central police forces, are embroiled in a military situation never war-gamed.

In the military’s scheme of things, however, Nariman Point has always been a po- tential target for an enemy in a conventional war. Mumbai’s “unconventional” attacks would rank as an act of war, in the language of most western countries, but Prime Minister Manmohan Singh stopped short of calling the terror strikes that.

The Prime Minister said in his address to the nation this evening that the external linkages of the terrorists were being investigated, though there has been no finger-pointing at Pakistan. But opinion in the government is growing that the terrorists were launched from Karachi’s neighbourhood.

Officials are suggesting that a distinction be drawn between the civilian Pakistani administration led by Asif Ali Zardari and fundamentalist outfits that oppose it and keep up a strident anti-India rhetoric.

“There is no way such an attack could have been carried out without a huge co-ordinated effort,” a senior defence ministry official said after a meeting of the cabinet committee on security and another called by defence minister A.K. Antony with the chiefs of the services. (Army chief General Deepak Kapoor is in South Africa.)

Yesterday, Indian and Pakistani home secretaries exchanged notes on co-operating against terrorists. Pakistan foreign minister Shah Mahmood Quereshi is in India and has held talks with Pranab Mukherjee.

There was a possibility the terrorists landed in Mumbai on inflatable rafts launched from a vessel out at sea. But western naval command chief, Vice-Admiral J.S. Bedi, said this was not “authenticated” information.

Naval and air force helicopters, along with the coast guard, have mounted surveillance in the seas off Mumbai and Goa. A naval Dornier aircraft from Goa was also flying reconnaissance sorties.

A trawler, MV Alpha, was searched but its crew weren’t detained as the navy found its papers in order.

But Vinod Masani, the owner of fishing trawler MV Kuber, found off Mumbai today after having left Porbandar on November 13, is being questioned.

The vessel was apparently carrying the body of one of its five crew members. The other four are missing.

Gujarat police feel that Mesani’s boat was hijacked. The boat, which had gone out for fishing 10 days ago, should have returned four days ago. The coast guard today found the boat five nautical miles from Mumbai.

Around 100 boats of Gujarat fishermen who strayed into Pakistan territory are now in the neighbouring country’s custody.

In Mumbai, the area command of the army headed by Major General R.K. Hooda has deployed 10 columns, around 1,000 troops, to cordon off the neighbourhoods in which the operations are taking place. Some soldiers from the “ghatak” (commando) platoons are in the thick of the firing along with the NSG.

In Delhi, the air force has put eight of its transport aircraft — two heavy-lift Ilyushin 76s, four AN 32s, an Avro and an Embraer — on standby. By this afternoon, the IL76s had flown two sorties to Mumbai and back ferrying NSG commandos.