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.

Pakistan closed its air space for Indian airlines and rejected New Delhi's suspension of a water sharing treaty on Thursday in retaliation for neighbouring India's response to a deadly militant attack in the Indian-ruled part of Kashmir.

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.