The battle between Indian troops and militants who attacked an air force base at Pathankot near the Pakistani border has entered a second night.
At least four attackers and seven Indian soldiers have died so far.
It is unclear whether all the militants have been killed, with the home secretary saying two gunmen were still at large.
The attack is being seen as a blow to an apparent Indo-Pakistani peace initiative launched just days ago.
Hopes for a thaw in relations were raised after Indian Prime Minister Narendra Modi paid an unexpected visit to his Pakistani counterpart, Nawaz Sharif.
Fresh gunfire and a blast were heard at the base on Sunday, more than a day after the attack started.