India said on Monday it had responded to 'unprovoked' small arms 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.

Anger in Indian-run Kashmir escalated on Monday over sweeping detentions in the hunt for the gunmen who carried out a deadly attack last week that New Delhi blames on arch-rival Pakistan.

In the days since, tensions have risen dangerously between India and Pakistan, which have fought two of their three wars over Kashmir.