Indian Prime Minister Narendra Modi vowed on Thursday to pursue, track and punish terrorists and their backers in a strong reaction to a deadly militant attack on tourists in Kashmir, where police have identified two of the gunmen as Pakistani.

It was the deadliest attack against civilians in years in Kashmir, a region claimed by both India and Pakistan that has been racked by violence for decades.

Twenty-six men were killed and 17 were injured when suspected militants opened fire at tourists in India's Jammu and Kashmir territory, police said.