Pakistani troops fired a surface-to-air missile Wednesday toward three Indian military helicopters flying over a marshy border region where India had shot down a Pakistani plane the day before.
Pakistan said it fired at two Indian fighter jets escorting the helicopters, which were carrying journalists to the crash site. Pakistani soldiers near the wreckage have set up mortars, anti-aircraft missiles and machine guns _ all pointing toward the border with India.
The second air clash in two days between the world's newest nuclear powers came just weeks after another confrontation cooled down in the northern Kashmir region. The direct confrontation threatened to further inflame hostilities on the subcontinent.
Associated Press journalists were on board two of the helicopters Wednesday when a missile flashed by. The chopper pilots turned fast and dove to avoid being hit.
"Two MiG-21 fighters approached the site of the wreckage. Our troops who were there engaged them and fired one time," Brig. Rashid Quereshi, a Pakistani military spokesman, told reporters in Pakistan. He said a surface-to-air missile was used but refused to elaborate.
The United States urged restraint by both sides. State Department spokesman James Rubin called on the South Asian rivals to respect a 1991 accord that bars flights close to their common border without prior warning.
"We urgently call on both sides to reinstitute this agreement in order to avoid further loss of life and further escalation and heightening of tensions," Rubin said.
Quereshi accused India of trying to steal the wreckage of the downed Pakistani plane so it can contend that it crashed in Indian territory.
India said Pakistan's French-built, twin-propeller Atlantique _ a surveillance and submarine-hunting aircraft _ was shot down Tuesday after penetrating six miles into Indian airspace and failing to respond to warnings. Pakistan said the aircraft was within its own territory.
Both nations claimed they had retrieved part of the wreckage. The remains of the plane may have been scattered on both sides of the border, where western India meets southeastern Pakistan.
Indian Air Marshal A.Y. Tipnis, the head of the air force, acknowledged Wednesday that "a major part" of the wreckage was in Pakistan.
Pakistan said 16 crew members were killed. More than 24 hours after the plane was shot down, no bodies had been found.
Tipnis said the Pakistani plane was shot down because Indian pilots feared it was armed. He said the aircraft could have been scouting possible invasion routes.
"In the event of an offensive, they could be looking for the possible creeks, the possible channels through which they can come in," Tipnis said at Naliya, an air base in western India.
In Pakistan's capital, Islamabad, Prime Minister Nawaz Sharif called a Cabinet meeting to discuss his country's response. The Cabinet's Defense Committee issued a statement warning that "all provocations and violations of Pakistan's airspace would be considered as hostile acts and given a befitting response."
India's Prime Minister Atal Bihari Vajpayee gathered top political leaders of all parties in New Delhi late Wednesday for a briefing on the confrontation.
India and Pakistan have fought three wars since they gained independence from Britain in 1947. The aerial clash was the first since they went to war in 1971.
The two nations came to the brink of war this summer during an 11-week confrontation in the mountains of Kashmir. India said Pakistani troops had infiltrated its territory, but Pakistan denied that its soldiers were involved and said all the fighters were local militants.
Indian and Pakistani troops have been fighting for control of the 20,000-foot Siachen Glacier in Kashmir _ the highest battlefield in the world _ since the early 1980s.
India said Wednesday its troops had driven back attacks by Pakistani forces there and had killed five Pakistani soldiers.