Blasts rang out across Indian Kashmir and the Sikh holy city of Amritsar in neighbouring Punjab state late on Friday, with the Indian military saying it was shooting down drones in the worst fighting with Pakistan in nearly three decades.

Pakistan's military says it has launched retaliatory strikes on sites in India, alarming world powers about further hostilities between the nuclear nations.

The confrontation between India and Pakistan intensified, with each accusing the other of strikes against military and civilian sites overnight.