SARGODHA, Pakistan — Five young Muslim American men arrested here Wednesday were on their way to the heart of the Taliban sanctuary in Pakistan’s tribal areas with the intention of training to fight against American troops in Afghanistan, Pakistani police authorities said Thursday.

Rahat Dar/European Pressphoto Agency

A view of the interior of the four-room home in a government housing complex in Sargodha, Pakistan where five American Muslims were arrested by Pakistani intelligence agencies.

The men, a tight circle of friends in their late teens and their 20s from the Washington suburbs, had been in contact through YouTube with a Pakistani militant with links to Al Qaeda before arriving in Pakistan on Nov. 30, said the Pakistani officials, who had firsthand knowledge of the case.

After touching down in Karachi, Pakistan’s biggest city, the men tried to join an extremist Islamic school near Karachi and approached another extremist organization, Jamaat-ud-Dawa, in the eastern city of Lahore, the officials said.

They were rebuffed in both places because of their Western demeanor and the fact that they did not speak the national language, Urdu, an investigator said. They then came here, to Sargodha, a city in the north of Punjab Province, en route to North Waziristan, said the police chief of Sargodha, Usman Anwar.

Sargodha, one of Pakistan’s biggest cities and home to the central command of Pakistan’s air force, is also known as a center for anti-India militant groups. North Waziristan is a haven for Al Qaeda in Pakistan; many Pakistani Taliban fighters have also fled there since the Pakistan Army’s assault their bases in South Waziristan.

The arrests were made at a four-room home in a government housing complex belonging to an uncle of the eldest of the group, Umer Farooq, 25, according to Chief Anwar.

“We had tips from local people and work of field officers that some foreigners were residing in some area of the city,” Chief Anwar said. “We watched them for a day or so and then arrested them.”

Mr. Farooq’s parents were staying at the house at the time, and his father, Khalid, was arrested as well. The police chief said the elder Mr. Farooq knew his son and the other men were being hunted by the F.B.I. but had failed to inform the authorities.

His mother, Sabria Farooq, was interviewed Thursday at the house. She said she and her husband had emigrated to the United States 20 years ago from Sargodha and had returned in September to start a computer business, similar to the one they have in the Virginia suburbs close to Washington.

Mrs. Farooq, who was veiled and wearing a traditional shalwar kameez, said that the family had informed the F.B.I. of their concern that their son had fled to Pakistan, but she did not make it clear whether they knew Umer had arrived in Sargodha.

A team of F.B.I. investigators interviewed the five men in Sargodha on Thursday, Chief Anwar said.

The arrests renewed concerns that American Muslim men with ethnic ties to Pakistan and other Muslim countries were increasingly at the center of terrorist plots aimed against the United States. Earlier this week, an American citizen of Pakistani background, David Coleman Headley, was charged in Chicago with helping plot the 2008 rampage in Mumbai, India, that left more than 160 people dead, including American tourists staying at a luxury hotel. Also charged was a Canadian born in Pakistan, Tahawwur Rana.

The police identified the others arrested in Sargodha as Ramy Zamzam, 22, a dental student of Egyptian background at Howard University, who was described as a sort of “ringleader”; Waqar Khan, of Pakistani background, who was reported to have family connections in Karachi; Ahmad A. Mini, 20, born in Eritirea; and Aman Hassan Yemer, 18, a native Ethiopian.

“They are U.S. nationals,” Chief Anwar said. “They have valid U.S. passports and valid Pakistani visas.”

The five men bonded together in the jihadi cause, watching jihadist video clips on YouTube that showed attacks by the Taliban on allied forces in Afghanistan, he said. The group also maintained a common e-mail address, Chief Anwar said. Employing a technique widely used among militants, they left their comments in the “draft” box of the e-mail address so that they could all easily read the comments.

The men appeared to have come to the attention of “Saifullah” — an Islamic militant with links to Al Qaeda — through their YouTube activities, the police chief said. Saifullah traced their e mail addresses through YouTube, Chief Anwar said.

After establishing the Internet connection with the militant, the men planned their journey to Pakistan and into the tough terrain of North Waziristan, where they intended to train around the border town of Miram Shah, a headquarters of the Afghan Taliban fighting against the American and NATO forces in Afghanistan, the police said.

The men were carrying laptops and maps of Miram Shah, as well as Kohat and Hangu, two major towns in the North-West Frontier Province that serve as the gateway to the tribal areas and North Waziristan, the police said.

Sargodha is about a seven-hour drive from Miram Shah over a route that is increasingly well traveled by Pakistani militants from Punjab who head to the Waziristans for training in explosives and weapons conducted by the Taliban and Qaeda operatives. In the last six months, 24 militants have been arrested in Sargodha, all of them with ties to the Taliban and Waziristan, the police said recently.

It was not clear, according to the police here, whether the men had been recruited to a specific militant or terrorist organization.

On Wednesday, a Pakistani official said that Khalid Farooq, the father of Umer, was believed to have ties to Jaish-e-Muhammad, a banned Islamic extremist group created by the government in the 1990s to conduct guerrilla attacks in the disputed territory of Kashmir. It was banned by the Pakistani government after the Sept. 11 attacks and has since joined forces with the Taliban and Al Qaeda in the lawless tribal areas of Pakistan.

Jawaat-ud-Dawa, which is based on the outskirts of Lahore and where the five men were apparently turned away, is an arm of Lashkar-e-Taiba, the Pakistani militant group at the center of the 2008 Mumbai terror attack.

Jawaat-ud-Dawa was declared a terrorist group by the United Nations last year but still operates in Pakistan. Its leader, Hafiz Saeed, was detained by the Pakistanis for six months.

A Pakistani investigator, who declined to be named because he was not authorized to speak about the case, said Khalid Farooq ran a small mosque out of his home in Virginia.

The five men seemed to have plenty of money, according to the police. Mrs. Farooq said that Mr. Khan had brought $25,000 from the United States for the trip. In Karachi, the men stayed in a “good local hotel” before moving to Hyderabad, Pakistan, to make contact with a religious school there, the police said.