Pakistan denies the incident involving two Indian soldiers which allegedly took place along the Kashmir border. Separately, a mob in India lynched two Muslim men over suspicion of stealing a cow; the men died of their injuries.
India's army accused Pakistani troops of killing two of its soldiers patrolling the de facto border in the disputed Kashmir region on Monday. India claims the bodies were later mutilated and has vowed to exact revenge.
Past accusations that Pakistani forces have mutilated dead Indian soldiers have outraged the Indian public and intensified the dispute between the two nuclear-armed neighbours over the Himalayan region.
"In a unsoldierly act by the Pak army, the bodies of two of our soldiers on patrol were mutilated," the Indian army said in an English-language statement, referring to Pakistani forces.
"Such despicable act of the Pakistan army will be appropriately responded."
The Indian army said Pakistani forces fired rockets and mortar bombs at two Indian posts on the Line of Control dividing Muslim-majority Kashmir between the two countries, in the Krishna Ghati sector.
Pakistan's military denied the allegations. It said there had been no violation of a ceasefire on the Kashmir frontier and that its soldiers had not mutilated the corpse of any Indian soldier.
Pakistan's military described its army as a "highly professional force" that shall "never disrespect a soldier, even Indian."
Fighting over Kashmir
India and Pakistan have faced off for decades across the Line of Control, an old ceasefire line through the region that both countries claim in full but rule in part. The two countries have fought at least two wars directly over Kashmir.
India accuses Pakistan of backing militants driven by extremism and encouraging them to attack Indian forces in Indian-administered Kashmir and, occasionally, in other parts of India.
Pakistan denies that and says India must hold negotiations on the future of Kashmir.
Peace talks between the two countries have been on hold for years and diplomatic engagement is at a minimum.
Mob in India kills two Muslims over suspected cow theft
In an unrelated incident, two people were arrested on Monday for cow vigilantism in Assam, a common occurrence in India, according to local media. The attack took place in India's northeastern state of Assam.
A 20-strong mob beat up Abu Halifa and Aiyazuddin Ali with sticks on Sunday, police said, after they were accused of plotting to steal cows for slaughter. The two young men succumbed to their injuries at a hospital.
Calls for beef ban
This Assam attack was the latest incident in a wave of violence being pinned on India's hardline Hindus. The religious group regard cows as sacred and many are demanding a blanket ban on butchering them.
Those calls growing even louder over the past three years since Prime Minister Narendra Modi came to power.
Most Indian states have banned the slaughter of cows, though the trade still operates unofficially in northern Uttar Pradesh state.
The state's Hindu leader, Yogi Adityanath, has been leading a crackdown in the state which last month saw 45,000 small meat shops shut down in less than 24 hours – in some cases, through the use of violence.