Since the Pakistani number was under surveillance, security agencies could locate the likely target of the terrorists.
The terrorists, who carried out the attack in Pathankot, were in regular touch with their handlers in Pakistan. The handlers even arranged a taxi for the terrorists by calling from a mobile number in that country.
Sources said the terrorists first used a Toyota Innova vehicle on Friday and it has been found that the driver was called from a Pakistan number.
Security agencies are questioning the driver and trying to find out whether he had been offering regular services to Pakistan-based smugglers, who have links with the terrorists, or was it a case of him not realising that it was a Pakistan number.
The driver of the Innova was called to a particular spot near Pathankot where the terrorists boarded the vehicle.
The sources said the car was used for travelling on an untarred road and dumped after a while as the rim of the vehicle got damaged.
The terrorist then hijacked an SUV (Mahindra SUV X500) in which a superintendent of the Punjab police was travelling along with a friend and a cook.
The SP and the cook were forced to leave the vehicle, while the friend, a jeweller, was taken as hostage.
The terrorists snatched a mobile phone and used it to dial the number in Pakistan which was used to call the driver of the Toyota Innova. They called their handlers thrice and once to a family member who was told that they were on a suicide mission.
Security agencies discovered from the Pakistani mobile number, the handlers were actively giving directions to the terrorists.
Since the Pakistani number was under surveillance, security agencies could locate the likely target of the terrorists, leading to the deployment of 160 National Security Guard commandos, Indian Army special forces besides others.
IMAGE: Security personnel stand guard outside the Indian Air Force base attacked by terrorists in Pathankot, Punjab. Photograph: PTI