Relations between India and Pakistan are cratering following a deadly attack in the disputed Himalayan region of Jammu and Kashmir that left more than two dozen tourists dead, raising fears of military escalation between the nuclear-armed rivals.

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.

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.