India said on Monday it had responded to 'unprovoked' firing from Pakistan along the de facto border for the fourth consecutive night, as it deepens its search for militants in the region following last week's deadly attack on tourists in Kashmir.

Following Tuesday's massacre of 26 mostly Indian tourists, hostilities have intensified between India and Pakistan over the hotly contested Kashmir region.

The Pakistani government said that if India followed through on a threat to block rivers it would take it as “an act of war.”