ISLAMABAD, Pakistan (AP) -- U.S. helicopters flew into Pakistan's militant-infested border region, but returned to Afghanistan after troops and tribesmen opened fire, intelligence officials said Monday. Washington denied the account.
The alleged incident late Sunday threatened new rifts between the United States and its key ally against terrorism days after a truck bomb struck a luxury hotel in Islamabad, killing 53 people.
Late Monday, Dubai-based TV channel Al-Arabiya said it had received a tape from a shadowy group calling itself "Fedayeen Al-Islam" - Arabic for "Islam commandos" - claiming responsibility for the bombing and urging Pakistan to end cooperation with Washington.
In the northwestern city of Peshawar, gunmen kidnapped Afghanistan's ambassador-designate Monday and killed his driver.
Pakistan is under growing U.S. pressure to act against al-Qaida and Taliban insurgents sheltering in its border region and blamed for rising attacks on coalition troops in Afghanistan and suicide bombings in Pakistan.
U.S. officials believe that al-Qaida's leaders, including Osama bin Laden, are hiding somewhere along the border.
A series of suspected U.S. missile strikes into the lawless region and a Sept. 3 raid by U.S. commandos said to have killed 15 people have highlighted U.S. impatience and angered many Pakistanis.
Two intelligence officials said on condition of anonymity because they were not authorized to speak to the media said two U.S. helicopters crossed one mile into Pakistan in the Alwara Mandi area in North Waziristan on Sunday.
Citing informants in the field, they said Pakistani troops and tribesmen responded with small arms fire, but it was not clear whether it was aimed at the choppers or just warning shots.
The helicopters did not return fire and re-entered Afghan airspace without landing, the officials said.
That account was denied by Pentagon officials. "There was no such incursion; there was no such event," said Defense Department spokesman Col. Gary L. Keck,
White House press secretary Dana Perino, talking to reporters on Air Force One about the report, said: "I would question that report, and I'm going to refer to the Department of Defense for the veracity of the report, but that has been debunked."
Pakistan's army said it had no information on the reported incursion across the poorly demarcated border.
Its military chief and newly elected President Asif Ali Zardari have said the missile strikes and incursions were violations of Pakistan's sovereignty and only fueled extremist violence.
Zardari, who is expected to meet President Bush in New York on the sidelines of the U.N. General Assembly this week, reiterated that he welcomed U.S. intelligence help, but not its troops.
"Give us the intelligence and we will do the job," he said in an interview with NBC. "It's better done by our forces than yours."
Some 270 people were wounded in the Saturday night attack on the heavily guarded Marriott hotel. The dead included the Czech ambassador and two U.S. Defense Department employees.
Most of the victims were Pakistanis, a fact that could bolster government efforts to present the struggle against the militants as its own battle, not one foisted upon it by Washington as many here think.
Al-Arabiya television said the group that claimed responsibility for the attack demanded an end to Pakistani-American cooperation against the militants and a halt to U.S. military operations in Pakistani tribal regions.
The U.S. Embassy warned its employees to limit their movement to travel to and from the embassy and to shopping for essential items only. It also warned all Americans to stay away from crowds, keep a low profile, and avoid setting patterns by varying times and routes for all required travel.
State Department spokesman Robert Wood said the attack showed the need for Pakistanis, Afghans and the U.S. to redouble efforts against extremists in the region.
"This was a heinous act that was committed by terrorists who have no interest in anything other than maiming and killing innocent civilians. And we're going to step up our efforts and work with the Pakistanis to do what we can," he said.
Interior Ministry chief Rehman Malik said Zardari, the prime minister and other top government officials were due to dine at the Marriott on Saturday, but they decided to change venue at the last minute. A spokesman for the hotel owner denied this.
"We didn't have any reservation of such a dinner that the government official is talking about," Jamil Khawar told The Associated Press.
Malik said that "perhaps the terrorists knew" the Marriott was the site of the government dinner, adding the decision to switch venues "saved the entire leadership."
Malik had said Sunday the Marriott was likely targeted because the attack would get tremendous attention. But Prime Minister Yousuf Raza Gilani said the bomber attacked the hotel only after security kept him from reaching parliament or the premier's residence, both less than a mile away.
Pakistani officials and analysts have said they expect the bombing investigation to lead to the border regions.
But Amir Mohammad, an aide to prominent Pakistani Taliban leader Baitullah Mehsud, said his chief was not involved and shared the nation's grief.
Mehsud was blamed by the last government for a suicide attack that killed Zardari's wife, the pro-U.S. politician Benazir Bhutto. Mehsud rejected the accusation.
Underscoring the deteriorating security, gunmen kidnapped Afghanistan's ambassador-designate Abdul Khaliq Farahi and killed his driver in Peshawar, said a spokesman for the mission in the city.
Also in the northwest, a suicide bomber killed nine security officers at a checkpoint in the Swat valley, and police killed 10 militants in a gunbattle elsewhere, officials said.
British Airways said it was temporarily suspending its flights to the country following the hotel attack.
The airline, which offered six flights to Pakistan each week, did not face a direct security threat, company spokesman Suhail Rehman said.