Pakistan’s defense chief warned of an “imminent” clash with India as a dispute over river water and blame for a terrorist attack last month in Kashmir escalates between the nuclear-armed neighbors.

India has alleged “cross-border” involvement from Pakistan in a terrorist attack that killed 26 men in the Indian-ruled part of Jammu & Kashmir on April 22nd. Pakistan denies any role and India has yet to present proof.

The move followed India’s suspension of the Indus Waters Treaty, a bilateral pact more than six decades old, which it said was in retaliation for the killing of 26 people in the disputed region of Kashmir last month. Pakistan has denied any involvement.