Thousands of armed Pakistani men left their homeland Saturday morning for Afghanistan vowing to fight a holy war against the United States.

Packed into buses, trucks and vans, more than 5,000 people left a northeastern Pakistan village on a mission: to enter Afghanistan's Kunar province and help the Taliban defend against any ground attacks by U.S. forces.

They’re not the only ones fueled by anger. Organizers said groups of similar numbers were coming together in other towns throughout the North West Frontier Province, an enclave of ethnic Pashtuns closely tied to Afghanistan.

In Temergarah on Friday night men of all ages gathered clutching assault rifles, machine guns, axes and swords, and even rocket launchers.

Holding a French rifle circa 1920, a retired Pakistani army officer seemed energized with ire. "I am an old man. I consider myself lucky to go — and to face the death of a martyr," said Shah Wazir, 70.

Military commanders resembling Taliban leaders with their black turbans and full beards instructed the masses of volunteers sitting on the ground on the ways of Islamic holy war, or jihad, the primary rule being to obey leaders.

Men eager to become warriors shouted anti-American slogans and embraced.

"It is a difficult time for Islam and Muslims. We are in a test. Everybody should be ready to pass the test — and to sacrifice our lives," said Mohammad Khaled, one brigade leader.

A local carpenter, Hussain Khan, carried a Kalashnikov and stood with his friend. The 19-year-old said he was leaving behind a fiancee and joining a worthy cause.

"Whether I come back alive or I am dead, I'll be fortunate because I am fighting in the service of Islam," Khan said.

The call for holy war came this week from Sufi Mohammad, an outspoken Muslim cleric who runs a madrassa, or religious school, in nearby Madyan. He exhorted "true Muslims" to mass and prepare to go to Afghanistan — to repel any U.S. ground incursions.

How they will get there, and what they will do upon arrival, is uncertain. Their way station before entering Afghanistan is Bajur, a borderland tribal village where volunteers from different areas will come together during the weekend.

In this region of Pakistan, Mohammad's organization, Tehrik Nifaz Shariat Mohammadi Malakand, or Movement for the Enforcement of Islamic Laws, has been embraced.

And the cleric's message — that, despite its insistence to the contrary, the United States is waging war on Islam itself — hits home.

"This is a strange occasion of world history," Mohammad said Friday. "For the first time, all the anti-Islamic forces are united against Islam."

It was impossible to verify how many supporters were actually en route to join him. In recent weeks, many militants have claimed far more backing than rallies eventually produce.

However, the numbers in Temergarah on Saturday morning — and the people jammed into trucks and on bus rooftops — suggested support was heavy. Mohammad's backers say the number to enter Afghanistan will reach 100,000.

"We are not worried about death," said Khaled, the brigade leader. "If we die in jihad, it is something much more greater than to be alive. And we will be taken into paradise."

The night before, men had massed by the thousands in Temergarah and other wind-whipped mountain villages in northeastern Pakistan's mountains.

Temergarah's streets were bustling with out-of-towners, their conversation ringing with anticipation. Pickup trucks roved around town with loudspeakers attached, calling people to gather and chant: "Afghanistan will be a graveyard for Americans."

Men huddled around radios, listening for news about the conflict; most tuned in to the BBC. People camped on porches, beneficiaries of local hospitality. Others slept on floors of public buildings. Mosques lodged as many as they could, and supplied food and blankets.

"I cannot tolerate the bombing and the cruelty of Americans. I must go," said Mamoor Shah, a medicine salesman who, at 18, already has a wife and child. "Muslims cannot keep silent."

For many young men, this is no mere rite of passage. It is religion — and it is blood, heritage and family.

"I'm going. My mother sent me to fight for our faith," said Farooq Shah, 21, a student from Buner, 50 miles away. When she told him to go, he had no Kalashnikov. So she went out, sold her jewelry and bought him one.

Another young man, Zabih Ullah, listed the people to defend in his jihad, or holy war — Usama bin Laden, his Arab friends, and Afghanistan itself.

And, Ullah said as he prepared for a war, no one will be permitted to get in the way.

"If anybody stops us, according to Islamic law we are allowed to fight jihad against him also," he said. "We will not put our arms down until the end of the American aggression."

The Associated Press contributed to this report.