NEW DELHI — A deadly attack on tourists in Indian-controlled Kashmir has again moved India and Pakistan closer to war as the two rivals downgraded diplomatic and trade ties, closed the main border crossing and revoked visas for each other’s nationals.

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

India's External Affairs Ministry said the Indus Water Treaty will be suspended after an attack in Kashmir left over two dozen dead.