﻿The US has said it is trying to find out whether Pakistan used US-built F-16 jets to down an Indian warplane, potentially in violation of trade agreements, as the standoff between the nuclear-armed Asian neighbours showed signs of easing.

Pakistan and India both carried out aerial bombing missions last week, and on Wednesday an Indian pilot was shot down over the disputed region of Kashmir in an incident that sparked fears of a full-blown war.

Pakistan returned the captured Indian pilot on Friday in a high-profile handover that Islamabad touted as a “peace gesture”, but both sides remain on high alert.

At the Line of Control (LoC), the de facto border between the two countries in Kashmir, there was relative calm, both armies said on Sunday. Indian security forces said they were carrying out mjor anti-militancy operations on their side of Kashmir and had shot dead two militants.

The US embassy in Islamabad said on Sunday it was looking into reports that Pakistan used F-16 jets to shoot down the Indian pilot, a potential 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,” an embassy spokesperson said. “We take all allegations of misuse of defence articles very seriously.“

Pakistan has denied using F-16 jets during the dogfight, but it has not specified which planes it used. It assembles Chinese-designed JF-17 fighter jets on its soil.

Pakistan has a long history of buying US military hardware, especially in the years after 2001 when Islamabad was seen as a key partner in the US-led “war on terror”.

Pakistan bought several batches of F-16 planes, built by Lockheed Martin Corp, from Washington before relations soured and the US cut off subsidised sales in 2016.

It is 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 said.

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 on Wednesday that Pakistani jets locked on to Indian targets to demonstrate Pakistan’s capacity to strike back at India, but then chose to fire at 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.

India said it struck at militant training camps, but Islamabad denied any such camps existed, as did villagers in the area when Reuters visited.

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 on Sunday it was relatively quiet.

“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.“

In Indian-administered Kashmir on Sunday, 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 member of a Pakistan-based militant group killed 40 Indian paramilitary police in a suicide bombing on 14 February.

The Indian government has come down hard on separatist groups operating in Kashmir, including by banning the Jamaat-e-Islami party, two of whose clerics were detained in raids on Saturday night.