The Pathankot base in the northern state of Punjab near the border with Pakistan was hit in a dawn raid Saturday that kicked off a 14-hour gunbattle. There was more firing Sunday.
It was not clear Monday whether any surviving attackers remained inside the base but troops were checking the area.
Security officials said they were focusing their search on a two-storey building that contained living quarters for families on the base where the militants had holed up.
“The operation continues at the base,” said a military official who asked not to be named.
“We are moving step by step to sanitise the area and it’s too early to say when the operation will be over.”
The attack — a rare targeting of an Indian military installation outside disputed Kashmir — may have been intended to undermine improving relations with Pakistan after a landmark visit to the country by Indian Prime Minister Narendra Modi last month.
Security officials suspect the gunmen belong to the Pakistan-based Jaish-e-Mohammed, the group that staged the 2001 attack on the Indian parliament which brought the two countries to the brink of war.
An AFP reporter at the scene said sporadic gunshots could be heard inside the air base Monday as army helicopters surveyed the site.
Pathankot houses dozens of jet fighters and is located just 50 kilometres (30 miles) from the Pakistan border.
Seven soldiers including a lieutenant-colonel in the elite National Security Guards commando unit were killed and 20 were injured in the assault at the base.
Such attacks are relatively rare outside the volatile disputed region of Kashmir.
But in July three gunmen said to be Pakistan-based Lashkar-e-Taiba militants killed seven people including four police in an attack in the Sikh-majority state of Punjab.