India accused Islamabad of supporting "cross-border terrorism." Pakistan has denied the accusation and a previously unknown militant group calling itself Kashmir Resistance has claimed responsibility for the attack.

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.

India and Pakistan both claim Kashmir in full but control it only in parts. Since India's partition and the creation of Pakistan in 1947, the nuclear-armed neighbours have fought wars over the territory.