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

The world's first drone war between nuclear-armed neighbours has erupted in South Asia.On Thursday, India accused Pakistan of launching waves of drones and missiles at three military bases in Indian territory and Indian-administered Kashmir - an allegation Islamabad swiftly denied.

India launched multiple Israeli-made Harop drones targeting Pakistan overnight and into Thursday, with one damaging a military site and wounding four soldiers, a Pakistani army spokesman said.