Pathankot: Heavily-armed Pakistani terrorists on Saturday attempted to storm the Indian Air Force base, triggering a day-long gunbattle in which three securitymen and all the five infiltrators were killed, days after Prime Minister Narendra Modi’s surprise stopover in Lahore.

With the obvious intention of destroying fighter jets and attack helicopters housed there, the group of terrorists in army fatigues attempted to storm the base, which is barely 35km from the international border with Pakistan, but failed to go beyond the outer periphery.

In heavy exchange of fire, a commando and two other personnel of the IAF were killed, along with all the five attackers.

At least six security men were also injured.

“I congratulate our armed forces and other security forces on successfully neutralizing all the five terrorists in ‘Pathankot Operation’," home minister Rajnath Singh tweeted after the 16-hour-long operation.

People aware of the developments in the home ministry said Singh tweeted after receipt of information that the operation was over.

The Prime Minister, who had taken a big political risk by going to Lahore, said in Mysuru that the attack was carried out by “enemies of humanity who can’t see India progress".

He expressed pride in the security forces, saying they did not let the terrorists succeed.

The attackers were believed to have infiltrated from Pakistan and there was speculation that they may belong to Jaish-e-Mohammad (JeM)-headed Maulana Masood Azhar of the Kandahar hijack episode.

Security personnel, who included commandos from the National Security Guard (NSG), Army and Air Force, appeared to be preparing for an extended operation as night fell and resistance continued.

The terrorists, who are said to have infiltrated three days ago, launched the first ever attack on an Indian air base at around 3.30am, their obvious targets being MiG-21 fighter aircraft and MI-25 attack helicopters.

Rajnath Singh did not rule out the possibility of the involvement of Pakistan-based JeM terror outfit in the attack.

“The case will be probed by the NIA, but the possibility of JeM being behind the attack cannot be ruled out," he said.

In the wake of the attack, defence minister Manohar Parrikar cut short his stay in Goa and returned to Delhi, where he held a high-level meeting which was attended by national security adviser Ajit Doval and the three service chiefs.

“Through timely and prompt action by all agencies, the likely plan of the terrorists to destroy valuable assets of the air force has been foiled," IAF said in a statement after the meeting.

The terrorists could not go beyond the ‘langar’ (eating place) near the outer perimeter of the IAF complex as the security forces were ready to take them on, officials said about the operation which was supervised directly by Doval.

Anticipating an attack after some armed men abducted an SP (Superintendent of Police) of Punjab Police on Thursday night, a team of NSG commandos had been rushed last night itself after the NSA held a series of meetings with the army chief and top Intelligence Bureau officials on Friday. An army detachment was also positioned at the air base, the sources said.

Defence sources said the terrorists could not enter the technical area of the IAF station, which is the base for MiG-21 fighter planes. Army had positioned two columns (comprising about 50 men) and a team of special forces at the Pathankot Air Force station prior to the attack, the people said.

Punjab police had also been put on alert and Additional DGP had been positioned in Pathankot to oversee the security situation, the sources said.

Army, Air Force personnel, Helicopters, NSG commandos and SWAT teams had been engaged to counter the militants in the coordinated counter operation, police said.

Top security officials in Delhi said the intent of terrorists clearly was to cause maximum destruction at the Air base which was thwarted in “one of the most successful counter-terror operations".

This was the second big terror attack in Punjab in less than a year. Three terrorists had stormed a police station in Dina Nagar in Gurdaspur in July last year before being eliminated in a 12-hour gunbattle.

An alarm had been sounded about today’s attack on Friday after Superintendent of Police Salwinder Singh and his two associates were abducted and thrashed by 4-5 suspected Pakistani terrorists in army uniform before being dumped some distance away.

They had slit the throat of the SP’s friend Rajesh. Those who attacked Salwinder Singh had also taken away his phone and used it suspectedly for making calls to Pakistan.

In the wake of the attack, Punjab has been put on maximum alert while security measures were also tightened in neighbouring Haryana and common capital of the two states — Chandigarh and Himachal Pradesh, official sources said. Security measures were beefed up at Chandigarh Air Force Stations at Chandigarh and Halwara in Punjab and at air base in Ambala.

Besides, security has also been beefed up at Army areas at Chandimandir and at Ambala cantt following terrorist attack at Pathankot. Security at railway stations of both Punjab and Haryana had also been increased, officials said. Security was also tightened on the Pathankot-Jammu National Highway.