New Delhi, (The Telegraph): The army aimed cannons mounted on armoured troop carriers at a two-storey building inside the Pathankot air force station from where militants were firing and razed it to rubble to kill the attackers late last night.

"We are checking through the rubble slowly," an officer said this afternoon. "I can tell you some human remains have been found but we can't be certain if there were one or two terrorists in the building."

In the evening, the National Security Guard's inspector-general (operations), Maj. Gen. Dushyant Singh, confirmed that "we have been able to eliminate a fifth terrorist". He said operations were still on.

There is no confirmation whether there are more militants inside the base.

The death of Lt Col E.K. Niranjan while examining the body of a militant on Saturday has forced a more gradual combing of the 1,600-acre air force station. Niranjan was killed in a grenade explosion. A militant had booby-trapped his own body before being killed.

The sheer amount of firepower that multiple security forces have used in the Pathankot operation that is spilling into its fourth day shows how the course of the battle changed after the deaths of five men from the Defence Security Corps and an air force Garud commando.

The security forces needed to use unmanned aerial vehicles, Mil Mi-35 helicopter gunships, mortars, machine guns and, finally, armoured vehicles to pin down the militants.

This even after there was specific intelligence, as disclosed by the government, that the attackers had infiltrated the border and were after high-value targets in the Pathankot region.

The sustained battle and the heavy casualties - including 20 wounded soldiers - have stirred questions whether the assessment of danger was off the mark.

But the government has denied there was either an intelligence failure or a deficiency in coordinating operations.

"These were well-trained terrorists and part of a suicide squad. When such kind of fidayeen attack takes place, it has the potential to cause huge damage. The complex is very big. The circumference of the airbase is 24km. Therefore, combing operations are also taking time," Arun Jaitley, the minister for information and broadcasting and finance, said in New Delhi after a meeting of the National Security Council.

He said security forces had confined the attackers to the point at which they had entered the station. He said the militants had been kept away from the technical area where aircraft were parked and that the "process is on for two more bodies". That would take the number of militants killed to six though the operational commander has so far confirmed five bodies.

Jaitley said "our security forces were completely successful" in ensuring that strategic assets were not damaged.

"A lot has been learnt from 26/11. In the 2008 Mumbai assault, more than 180 people were killed. The terrorists were successful in severely denting us. However, this time, our reaction was prompt. The precautionary measures were taken in time. The militants were curtailed at an early stage," said the minister.

Security establishment sources said that after the government received information about the militants on the morning of January 1, a general alert had been sounded at all installations in the Pathankot region.

The air force station, with a 23km perimeter wall and five gates, stretches to National Highway 1A on one side. On another, it is hugged by a canal, the Barphani Nullah, that eventually flows into the base.

The base is divided into domestic and technical areas. The domestic area houses living and administrative quarters. The technical area, apart from the runway, has hangars and workshops.

Among the first troops to be called in were the 11 Jammu and Kashmir Rifles (JAKRIF), part of the Mamoon Brigade. They were tasked to protect the technical area. The 1 Para (special forces) were also called in.

The JAKRIF men took position before the National Security Guard (NSG) unit from Manesar, near Delhi, reached Pathankot on the night of January 1-2.

Initially, Brig. Anupinder Singh Belvi, commander of the Mamoon Brigade, was the task force commander.

The responsibility was effectively vested on Maj. Gen. Dushyant Singh later.

Although the major general is an army officer - indeed he commanded a division in Jammu neighbouring Pathankot before his current assignment - he is technically deputed to the home ministry that is the parent of the NSG.

The overall responsibility for the security of the Pathankot Air Force Station rests with Air Commodore Jagmeet Singh Dhamoon who is the Air Officer Commanding (AOC) of the base.The preliminary suspicion is that one of two teams of militants had managed to sneak into the base through the canal and had taken up position before the full deployment of troops. The point at which the canal cuts into the compound of the base is barred with an iron grille.

Sources in the army said that at first, two columns (of about 100 troops each) were deployed in the technical area. These men engaged the militants after they had attacked the DSC and the Garud on January 1 night.

Subsequently, the army deployment was increased to six and then to eight columns.

Last night, the militants began firing from a two-storey house that was the single (as opposed to married) airmen's quarters opposite the base canteen. By the time they had entered the building, the men had evacuated.

It was this building that the BMPs - the infantry combat vehicles - aimed their cannons at.

Indian leads: Pak

Pakistan said late tonight that it was working on "leads" provided by India and extended the deepest condolences to the government and people of India on the "unfortunate terrorist incident".

An Indian official confirmed that the government had shared details of telephone intercepts.

A statement in Islamabad said: "We understand the pain of many families

who have lost their dear ones in this tragedy as Pakistan itself is a major victim of terrorism."

It added: "Living in the same region and with a common history the two countries should remain committed to a sustained dialogue process. The challenge of terrorism calls for strengthening our resolve to a cooperative approach."

The statement came hours after uncertainty crept into the scheduled foreign secretary talks.

Photo credit: The Telegraph