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.

At least 26 people were killed and 17 others wounded when gunmen opened fire on tourists in Indian-controlled Kashmir, the worst assault in years targeting civilians in a restive region that has seen an anti-India rebellion for more than three decades.