New Delhi, India (CNN) -- India and Pakistan traded bitter accusations Wednesday after New Delhi said Pakistani troops had killed two of its soldiers in the disputed territory of Kashmir, a flash point between the two nations since their creation.
Indian Foreign Secretary Ranjan Mathai summoned the Pakistani High Commissioner and "lodged a strong protest" about what India alleges took place Tuesday, increasing the strain on ties between the two nuclear-armed neighbors.
But Pakistan reiterated its denial of the accusations, saying India was trying to distract attention from a weekend clash in the Himalayan territory that left a Pakistani soldier dead.
India asserts that Pakistani troops took advantage of thick fog in a wooded area on Tuesday to cross over to its side of the Line of Control, the de facto border between the two nations in Kashmir.
The Indian military says one of its routine patrols spotted the Pakistani troops in the Mendhar sector of Poonch district, and a firefight lasting about 30 minutes ensued, during which two Indian soldiers were killed.
The Indian government on Wednesday accused Pakistani troops of subjecting the two soldiers' bodies to "barbaric and inhuman mutilation," calling the alleged actions "highly provocative."
The Pakistani foreign ministry rejected the allegations that its troops had crossed the Line of Control and killed Indian soldiers.
"These are baseless and unfounded allegations," the foreign ministry said. "Pakistan is prepared to hold investigations through the United Nations Military Observes Group for India and Pakistan on the recent cease-fire violations on the Line of Control."
Pakistan said it is committed to "a constructive, sustained and result-oriented process of engagement with India," and is working to ensure their relations are normal.
Indian External Affairs Minister Salman Khurshid urged his compatriots to keep cool heads despite widespread outrage about the reported attack on the Indian soldiers.
While noting "enormous concern among ordinary people" and a "tremendous amount of stress" in the government, he said Wednesday, "I think it's important that we remain in control of the situation and we don't allow emotions to run away with the situation."
Speaking in an interview with CNN affiliate IBN, Khurshid said it was necessary to wait for Pakistan's formal response to India's diplomatic protest.
In the Sunday clash, according to the Pakistani military, Indian troops crossed the Line of Control and attacked a military post. Pakistani army troops repulsed the attack, but one Pakistani soldier was killed and another critically injured, Pakistan said.
The Indian Defense Ministry, however, said Pakistani troops opened fire unprovoked on Indian posts in the north Uri sector of Indian-administered Kashmir. Indian troops retaliated and forced Pakistani troops to stop firing, the ministry said. It did not immediately report the number of casualties.
The disputed territory lies in India's Kashmir Valley, separated from Pakistan by the 450-mile Line of Control.
The Pakistani army filed a formal complaint over Sunday's incident with United Nations military observers, said Kieran Dwyer, spokesman for the agency's peacekeeping operations. The U.N. group will conduct an investigation.
No complaint had been filed by either army over Tuesday's incident. U.N. officials urged "both sides to respect the cease-fire and de-escalate tensions through dialogue," Dwyer said.
The two South Asian neighbors have had a cease-fire along the de facto border since November 2003. But it has been violated repeatedly, with both sides accusing the other of offenses.
Bilateral talks were suspended in 2008 after an attack by Pakistani militants in Mumbai, India's most populous city, killed more than 160 people. The negotiations have since resumed.
The conflict over Kashmir dates back to 1947, after Britain relinquished control of the Indian subcontinent, giving birth to modern India and Pakistan.
Kashmir was free to accede to either nation. Maharaja Hari Singh, the ruler of the kingdom at the time, initially chose to remain independent but eventually opted to join India, thereby handing key powers to the central government in New Delhi. In exchange, India guaranteed him military protection and vowed to hold a popular vote on the issue.
The South Asian rivals have fought two full-scale wars over the territorial issue.
Islamabad has always said that majority-Muslim Kashmir should have been a part of Pakistan. A United Nations resolution adopted after the first war called for a referendum allowing the people of Kashmir to choose which country they wanted to join, but that vote for self-determination has never been held. Pakistan wants that referendum to take place.
India says that Pakistan lends support to separatist groups fighting against government control and argues that a 1972 agreement mandates a resolution to the Kashmir dispute through bilateral talks.
CNN's Harmeet Shah Singh reported from New Delhi, and journalist Habib Nasir reported from Islamabad, Pakistan. CNN's Shaan Khan in Islamabad; journalist Mukhtar Ahmad in Srinagar, India; and CNN's Aliza Kassim in Atlanta contributed to this report.