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.

Will India be able to stop the Indus river and two of its tributaries from flowing into Pakistan? That's the question on many minds, after India suspended a major treaty governing water sharing of six rivers in the Indus basin between the two countries,