India said it would immediately suspend the Indus Waters Treaty with Pakistan as part of measures to downgrade diplomatic ties with its neighbour after militants attacked tourists in Kashmir, killing 26 men.

The agreement split the Indus and its tributaries between the two countries and regulated water sharing. India was granted the use of water from three eastern rivers - Sutlej, Beas and Ravi - while Pakistan was granted most of the three western rivers - Indus, Jhelum and Chenab.

India’s unprecedented move to suspend a water-sharing pact in response to a gun attack in Kashmir earlier this week threatens to hurt crops and power generation in Pakistan, just as temperatures begin to rise sharply in the pre-monsoon summer.