An attack on tourists in India's Himalayan territory of Kashmir this week sparked a new crisis between nuclear armed South Asian neighbours India and Pakistan, with New Delhi blaming militants with "cross-border linkages" for the killings.

The nuclear-armed rivals, which both claim Kashmir and administer separate parts of it, are at a dangerous crossroad after Tuesday’s militant attack, analysts said.

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.