The United States is trying to find out if Pakistan potentially violated an international agreement by using a US-built F-16 jet to shoot down an Indian warplane.

Pakistan and India both conducted aerial bombing missions last week, including a clash which saw an Indian jet shot down over the disputed region of Kashmir.

The US embassy in Islamabad said it was looking into reports that Pakistan used F-16 jets which would be a violation of Washington's military sale agreements that limit how Pakistan can use the planes.

"We are aware of these reports and are seeking more information," a US embassy spokesperson said.

"We take all allegations of misuse of defence articles very seriously."

Pakistan shoots down Indian fighter jets: Reaction in pictures Show all 28 1 /28 Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistan shoots down Indian fighter jets: Reaction in pictures Activists of Al-Badr Mujahideen, an islamic militant group, burn an effigy of Indian Prime Minister Narendra Modi during an anti-India protest in Peshawar, Pakistan AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures A Pakistani girl holds a light candle during a vigil for peace in Lahore on March 3 AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures School children react as they celebrate the release of Indian Air Force pilot Wing Commander Abhinandan Varthaman by Pakistan at a school in Ahmedabad Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Indian pilot, Wing Commander Abhinandan, stands under armed escort near Pakistan-India border in Wagah Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Indian Border Security Force soldiers patrol along the border with Pakistan EPA Pakistan shoots down Indian fighter jets: Reaction in pictures A videograb allegedly shows the captured Indian Air Force pilot in the custody of Pakistani military SWNS Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani civil society activists hold anti-war signs during a peace rally in Islamabad AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani civil society activists hold anti-war signs during a peace rally in Islamabad AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures Activists of Al-Badr Mujahideen, an islamic militant group, burn an effigy of Indian Prime Minister Narendra Modi during an anti-India protest in Peshawar, Pakistan Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Kashmiri villagers look on at the smouldering wreckage of an Indian fighter jet after it was shot down by the Pakistani military AP Pakistan shoots down Indian fighter jets: Reaction in pictures Indian soldiers and Kashmiri onlookers stand look on as an Indian army helicopter lands near the site where an Indian Air Force jet was shot down by the Pakistani military AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures An Indian soldier gestures near the wreckage of an Indian Air Force fighter jet that was shot down by the Pakistani military AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures Supporters of a Pakistani religious group Islami Jamiat-e-Talaba brand Indian Prime Minister Narendra Modi a terrorist at a rally to condemn Indian aggression AP Pakistan shoots down Indian fighter jets: Reaction in pictures Indian soldiers and Kashmiri villagers look on at the smouldering wreckage of an Indian fighter jet after it was shot down by the Pakistani military AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures India's Border Security Force soldiers patrol along the fenced border with Pakistan on February 26 Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Protesters in Pakistan march against Indian Prime Minister Narendra Modi after the Indian airstrike on allege Pakistan terrorist camp EPA Pakistan shoots down Indian fighter jets: Reaction in pictures Supporters of India's ruling Bhartiya Janta Party workers hold Indian flags as they celebrate the Indian airstrike on allege Pakistan terrorist camp AP Pakistan shoots down Indian fighter jets: Reaction in pictures Protesters in Pakistan march against Indian Prime Minister Narendra Modi after the Indian airstrike on allege Pakistan terrorist camp EPA Pakistan shoots down Indian fighter jets: Reaction in pictures People in India burn an effigy that represents Pakistan as they celebrate the Indian airstrike on allege Pakistan terrorist camp Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Indian soldiers and Kashmiri villagers look on at the smouldering wreckage of an Indian fighter jet after it was shot down by the Pakistani military AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures Bhartiya Janta Party workers hold Indian flags as they celebrate the Indian airstrike on allege Pakistan terrorist camp EPA Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani Kashmiris in the border town of Chakoti walk past India-bound cargo trucks that are parked as the road to India is closed AP Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani Army soldiers escort journalists to the scene where Indian fighter jets struck in a violation of Pakistani airspace EPA Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani Army soldiers escort journalists to the scene where Indian fighter jets struck in a violation of Pakistani airspace EPA Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani Army soldiers escort journalists to the scene where Indian fighter jets struck in a violation of Pakistani airspace EPA Pakistan shoots down Indian fighter jets: Reaction in pictures Workers enter a concrete bunker that they have built in a residential area near the border Reuters Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani soldiers and journalists gather at the site where Indian fighter jets struck in a violation of Pakistani airspace AFP/Getty Pakistan shoots down Indian fighter jets: Reaction in pictures Pakistani soldiers and journalists gather at the site where Indian fighter jets struck in a violation of Pakistani airspace AFP/Getty

It is however not clear what exactly these so-called "end-user agreements" restrict Pakistan from doing.

"The US Government does not comment on or confirm pending investigations of this nature," the US embassy added.

Pakistan has denied using F-16 jets during the dogfight that downed an Indian warplane but has not specified which planes it used.

On Thursday Indian officials displayed to reporters parts of what they called an air-to-air missile that can only be fired from F-16 jets, alleging they were used to bomb its side of the disputed Kashmir border on Wednesday.

A Pakistan military spokesman told reporters that Pakistani jets "locked" on Indian targets to demonstrate Pakistan's capacity to strike back at India, but then chose to fire in an empty field where there would be no casualties.

Pakistan said its mission on Wednesday was in retaliation for India violating its airspace and sovereignty a day earlier, when Indian jets bombed a forest area near the northern city of Balakot.

Cross-border shelling in the past few days has killed seven people on the Pakistani side and four on the Indian side of Kashmir.

But there was relative calm at the Line of Control (LoC), the de facto border of Kashmir, on Sunday.

"By and large the LoC was calm last night but you never know when it will become active again," said Chaudhry Tariq Farooq, a minister in Pakistani Kashmir.

"Tension still prevails."

Captured Indian pilot Abhinandan Varthaman crosses back to India

In Indian-administered Kashmir, troops shot dead two militants after a three-day gun battle that also killed five security force personnel, taking the total death toll to 25 in the past two weeks.

The fresh anti-militancy drive was launched after a Kashmiri suicide bomber, a member of a Pakistan-based militant group, killed 40 Indian paramilitary police on 14 February.