Investigators say the terrorists, suspected to belong to the Pakistan-based Jaish-e-Mohammad, probably entered India through the Ugh river. The attackers are suspected to have infiltrated and entered the air force base in two teams.
On Thursday night, one of the groups abducted Gurdaspur SP Salwinder Singh, his cook Madan Gopal and a friend of the policeman as they were returning from Pathankot. They said they were beaten up and pushed out of the vehicle by four armed men in fatigues, who drove away in the Punjab Police officer's SUV.
The terrorists used the car to enter the air force base.
In an intercepted call, handlers for the terrorists were reportedly heard asking why the second group of attackers had fallen behind.
Six terrorists have been killed in the gunbattle at the air base which began on Saturday morning.
At least seven security personnel have died and 20 are injured.
The Border Security Force will submit a report to the Home Ministry on the possible routes used by the terrorists to infiltrate into India.
Since Saturday morning, the sprawling Pathankot air base, spread over several kilometres, has been swarming with air force commandos, troops from the elite National Security Guard and the local police.
The base houses a fleet of India's Russian-origin MiG-21 fighter jets and Mi-25 and Mi-35 attack helicopters.