India is vowing to hunt down terrorists "to the ends of the earth" as tensions are escalating with Pakistan in the wake of a deadly attack in India's Kashmir region.

It comes after India's retaliatory measures following a militant attack in Kashmir killed 26 tourists on Tuesday.

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.