Relations between India and Pakistan are cratering following a deadly militant attack in Indian-administered Kashmir that has sparked tit-for-tat reprisals and raised fears of another military escalation between the nuclear-armed rivals.

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 Indian military says Pakistani soldiers fired at Indian posts all along the highly militarized frontier in disputed Kashmir as tensions flare over attack on tourists.