India says it is not aware of the incident which reportedly killed four Pakistani soldiers in disputed Kashmir.
Sunday’s incident between the nuclear-armed neighbours occurred in Athmaqam town of Neelum district in Pakistan-administered part of Kashmir region, according to the Pakistani military officials.
“The vehicle fell into the Neelum river. Four soldiers drowned. Body of one shaheed (martyr) recovered, search for remaining three in progress,” the military said in a short statement.
Pakistan’s Prime Minister Nawaz Sharif condemned the incident and “praised the prompt response by Pakistan army in thwarting the attack”, a statement by his office said.
Lieutenant Colonel Rajesh Kalia, a spokesman for India’s defence ministry, said he had no knowledge of the incident, Reuters news agency reported.
Kashmir has been divided between India and Pakistan since the end of British colonial rule in 1947. Both claim the Himalayan territory in full and have fought two wars over the mountainous region.
The hostile neighbours regularly exchange mortar fire across the Line of Control, the de facto Kashmir border, despite signing a ceasefire in 2003.
At least nine people were killed and seven others wounded last November when cross-border fire hit a passenger bus in the village of Nagdar in Pakistan-administered Kashmir.
Tensions reached dangerous levels again last September with both sides blaming one another for cross-border raids.
There have since been repeated outbreaks of deadly firing across the frontier.
India and Pakistan have fought three wars – in 1948, 1965 and 1971 – since they were partitioned in 1947, two of which were fought over Kashmir.
More than 70,000 people have reportedly been killed in the conflict since 1989. India maintains more than half a million troops in the disputed region.