Indian troops have fired across the disputed Kashmir border and killed a Pakistani soldier, Pakistan's military says. It is the third deadly incident in the Himalayan region in recent days.
Pakistan said the shooting was unprovoked, while the Indian military said its troops responded to fire from soldiers across the frontier.
The tit-for-tat fighting threatens to reverse recent progress Pakistan and India have made in improving their historically antagonistic relationship. The two countries have fought three major wars since they achieved independence from British India in 1947, two of them over Kashmir.
The relationship reached a recent low point in 2008 when Pakistani gunmen killed 166 people in the Indian city of Mumbai. t has improved significantly since then, and the two countries have taken steps to improve cross-border trade and ease travel restrictions. But key issues, including Kashmir, remain unresolved.
The mountainous region is divided between the two countries, but both claim the area in its entirety. A ceasefire over Kashmir has largely held for about a decade, despite periodic firing across the disputed border that sometimes causes casualties.
The danger from today's violence is that it comes on the heels of two more serious incidents in which Pakistan and India accused each other of sending troops across the border and killing soldiers, the first such accusations since the ceasefire went into effect in 2003.
The Pakistani army said the latest incident occurred when Indian troops fired at a post in an area of Pakistan-held Kashmir called Battal, killing a soldier named Havildar Mohyuddin. Pakistan said the shooting was "unprovoked".
But the Indian military said its troops responded after Pakistani soldiers fired on their positions. "Our troops retaliated and an intermittent exchange of gunfire is continuing," said Indian army spokesman Col R.K. Palta. "It's yet another ceasefire violation by the Pakistani troops."
The most recent round of violence started on Sunday, when Pakistan accused Indian troops of raiding an army post and killing one of its soldiers. India denied raiding the Pakistani post, and said Pakistani shelling had destroyed a home on its side of the frontier.
On Tuesday, India said Pakistani soldiers crossed the border and attacked an army patrol, killing two Indian soldiers and decapitating one of them. Pakistan has denied the allegations.