India's Prime Minister Narendra Modi says the gunmen behind a terrorist attack on tourists in the Kashmir region "will not be spared!"

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

Indian officials said the army had a brief exchange of fire with Pakistani soldiers along their highly militarized frontier in the Himalayan region of Kashmir, as the nuclear-armed rivals ramped up tit-for-tat diplomatic offensive following a deadly attack on tourists in the disputed area.