Indian claims of downing a Pakistan F-16 jet over Delhi-administered Kashmir during the latest row with Islamabad are unfounded, according to Finnish investigative website Bellingcat.

Bellingcat, known for its accurate analysis of war zones such as Syria, Iraq and Ukraine, found no “compelling evidence” that an F-16 was shot down by India over Kashmir.

Finnish expert Veli-Pekkalt concluded that “all signs point to a downing of a Soviet-era MiG 21 belonging to the Idnian Air Force, instead of a Pakistani F-16 as claimed by India.

Pictures shared by both Pakistan and India were examined by the website before reaching the damning conclusion, which casts doubts on Delhi’s official narrative of the events in Kashmir.

A top Indian minister said on Saturday the government would not share proof that "a very large number" of militants were killed in air strikes inside Pakistan this week, after doubts were raised there were any casualties in the attack that stoked tensions between the nuclear-armed rivals.

The flare up appeared to be easing on Saturday after Pakistan handed back a captured Indian fighter pilot on Friday night, amid efforts by global powers to prevent another war between the arch enemies.

However shelling across the Line of Control (LoC) that acts as a de facto border in the disputed Kashmir region, a frequent feature in recent weeks, continued, said military officials on both sides.

Hostilities escalated rapidly following a suicide car bombing on Feb. 14 that killed at least 40 Indian paramilitary police in Indian-controlled Kashmir. India accuses Pakistan of harbouring the Jaish-e Mohammad Islamist group that claimed the bombing.

Indian warplanes carried out air strikes on Tuesday inside northeast Pakistan's Balakot on what New Delhi called militant camps. Islamabad denied any such camps existed, as did local villagers in the area when Reuters visited.

Nevertheless, Pakistan retaliated on Wednesday with its own aerial mission.

Pakistan said the Indian bombs hit a largely empty hillside without hurting anyone. Some Indian opposition leaders have asked the government to share evidence of the strikes.