Officials say that the number of troops killed in an attack on an Indian air force base has risen to six after four soldiers succumbed to injuries sustained in the hourslong gunbattle near the border with Pakistan. Four suspected militants were also killed in the fighting.

Air force spokeswoman Rochelle D'Silva says combing operations to secure the Pathankot air force base were continuing by late Sunday morning.

Saturday's attack came just a week after the first visit to Pakistan in 12 years by an Indian prime minister. Police said they're investigating whether the gunmen came from the Indian portion of Kashmir, where rebels routinely stage attacks, or from Pakistan.

The attack began just before dawn and lasted about 14 hours.