Indian Defense Minister A. K. Antony told Parliament that the soldiers were attacked by “20 heavily armed terrorists along with persons in Pakistani army uniforms.” (JAIPAL SINGH/EPA)

Five Indian soldiers were killed in an ambush along the Himalayan border with Pakistan, Indian officials said Tuesday, triggering fresh hostility with Islamabad that could imperil efforts to resume peace talks.

Indian Defense Minister A. K. Antony told Parliament that the soldiers were attacked by “20 heavily armed terrorists along with persons in Pakistani army uniforms.” Five were killed and one was wounded, Antony said, adding that the Indian government had “lodged a strong protest” with Islamabad.

Pakistan’s Foreign Affairs Ministry, in a news release, called the allegations “baseless and unfounded.”

“Our military authorities have confirmed that there had been no exchange of fire that could have resulted in such an incident,” the statement said. “Such ill-founded reports,” the ministry added, have “the potential of vitiating the atmosphere.”

The accusations could adversely affect a proposal sent by Pakistani Prime Minister Nawaz Sharif to New Delhi recently, seeking to resume the stalled dialogue process. Ties between the nuclear-armed neighbors grew strained in January after a similar border incident in which both countries accused the other of crossing the border and killing soldiers. New Delhi accused Pakistani troops of decapitating one soldier, a charge denied by Islamabad.

India and Pakistan have fought two of their three wars over the disputed Muslim-majority Himalayan region of Kashmir, which both countries claim as their own. The roller-coaster relations between the two have frequently stalled peace efforts even as officials on both sides have struggled to keep talks on track.

India’s newly appointed foreign secretary, Sujatha Singh, had said that India would be “picking up the threads” of peace talks with Islamabad. Prime Minister Manmohan Singh and Sharif were scheduled to meet in New York next month on the sidelines of the U.N. General Assembly.

But Monday’s incident may cast a shadow over these overtures. Indian army officials told reporters that the attack occurred in a mountainous area of Kashmir late Monday, near the cease-fire line and a border fence. The Indian soldiers were conducting a patrolling exercise called “area domination,” the officials said.

After hearing about the bloodshed, angry Indian lawmakers shouted slogans in Parliament, and members of the main opposition group, the Bharatiya Janata Party, demanded that the government immediately call off the proposed talks.

“It is an extremely unfortunate incident,” R.P.N. Singh, deputy minister for home, told reporters in New Delhi. “If Pakistan wants to have better relations with India, I think this is not the way.”

Senior government minister Farooq Abdullah said the “hand of friendship cannot be one-

Antony told lawmakers that the Indian army had foiled 17 attempts by Pakistani militants to enter Indian territory this year. He added that there were 57 incidents of cease-fire violations by Pakistani troops this year, an 80 percent jump compared with the same period last year.

“Did we drop our guard on the border and lull ourselves into complacency?” asked K. C. Singh, former diplomat and foreign affairs commentator. “Where is the need to rush in for a high-level dialogue now?”

On Monday, the Pakistani organization running cricket for blind players had invited its counterpart in India for a visit in February.

Shaiq Hussain in Islamabad contributed to this report.