Pakistan's Prime Minister Imran Khan will stage an emergency parliamentary session and meet with the body in control of Islamabad's nuclear arsenal in response to India's first air strikes on Pakistan since 1971.

Key points: Indian fighter jets struck an area 50 kilometres into Pakistan on Tuesday

Indian fighter jets struck an area 50 kilometres into Pakistan on Tuesday India said the strike was in response to a terrorist attack that killed 44 Indian police

India said the strike was in response to a terrorist attack that killed 44 Indian police Pakistan said its own warplanes had scattered Indian jets, forcing them to drop their payload over uninhabited areas

The two nuclear-armed neighbours have fought three wars since partition in 1947, and the majority of them have been over Kashmir — a territory both India and Pakistan claim in full.

The air strike near Balakot, a town 50 kilometres into Pakistan from the Indian border, was the deepest raid launched by India since the last of its three wars with Pakistan, but there were competing claims about any damage caused.

India said its air force jets hit a training camp of Jaish-e-Mohammed (JeM), the militant group that claimed credit for a February 14 suicide bombing attack that killed more than 44 Indian paramilitary police in Kashmir.

Indian Foreign Secretary Vijay Gokhale said "a very large number" of militants were killed in the strikes in north-east Pakistan, which were launched as a result of government intelligence that JeM was planning more attacks

"The existence of such training facilities, capable of training hundreds of jihadis, could not have functioned without the knowledge of the Pakistani authorities," Mr Gokhale said.

A senior Indian Government source said 300 militants had been killed in the strikes and warplanes had ventured as far as 80 kilometres inside Pakistan, but they provided no evidence.

'You all know what that means'

Pakistan said its Prime Minister would "engage with global leadership to expose irresponsible Indian policy". ( Pakistan Press Information Department via AP )

Pakistan has disputed India's claims of success, and later said that its own warplanes had scattered Indian jets and forced them to drop their payload over uninhabited areas, resulting in zero casualties.

An Indian official later said air force jets intercepted Pakistani planes in Kashmir in a separate incident, and said an Indian jet crashed, killing two pilots and a civilian.

Pakistan's National Security Committee (NSC), comprising top officials including Mr Khan and army chief Qamar Javed Bajwa, said the Prime Minister would "engage with global leadership to expose irresponsible Indian policy".

A government spokesperson added that a command and control authority meeting, which decides over the use of nuclear weapons, had been convened for Wednesday, and noted: "You all know what that means."

Speaking to the ABC's AM program, Dhruva Jaishankar from the Brookings Institute said Pakistan's retort was an attempt to quell further military escalation.

"Pakistan has reason to deny and downplay the effectiveness of the strikes," Ms Jaishankar said.

"It helps to manage domestic political opinion and ensure that there's not a demand for escalation, and India, I think, has been very clear that something did occur," she said.

Indians celebrate Pakistani strike

Supporters of India's ruling Bhartiya Janata Party have celebrated the airstrike on Pakistan. ( AP: Altaf Qadri )

While the results of the strikes in the early hours of Tuesday were disputed, that did not stop many in India from believing their government's version of events.

"Modi ji (Indian Prime Minister Narendra Modi) has finally done it," said Sandeep Sharma, a driver in the Jammu region of India's border state of Jammu and Kashmir.

"There's a lot of anger against Pakistan here."

India's opposition leaders, many of whom have banded together against the ruling Bharatiya Janata Party (BJP), congratulated the Indian Air Force (IAF), though they stopped short of praising the Prime Minister.

"I salute the pilots of the IAF," Rahul Gandhi, leader of India's main opposition Congress, said in a tweet.

In a village 100 metres from the Line of Control that acts as the de facto border with Pakistan, men gathered around a bunker for security forces that is under construction and shouted slogans hailing India.

ABC/Reuters