American and Pakistani intelligence agents are exploiting a growing rift between Arab members of Al Qaeda and their Central Asian allies, a fissure that's tearing at the network of Islamic extremists as militants compete for scarce hideouts, weapons and financial resources, counterterrorism officials say.

The rivalry may have contributed to the arrest last week of one of Usama bin Laden's top lieutenants, a Libyan described as Al Qaeda's No. 3 and known to have had differences with Uzbeks.

Captured Uzbek (search), Chechen (search) and Tajik (search) suspects have been giving up information about the movements of Arab Al Qaeda militants in recent months, four Pakistani intelligence agents told The Associated Press, leading to a series of successful raids and arrests.

"When push comes to shove, the Uzbeks are going to stick together, and the Arabs are going to stick together," said Kenneth Katzman, a terrorism expert with the Congressional Research Service (search) in Washington. "I think the Uzbek guerrillas have had no home. Some of this could be a battle for survival."

The Pakistani agents, who hold sensitive jobs in various military and intelligence agencies in several cities, all spoke on condition their names not be used.

U.S. officials declined to comment on the schism. One, however, noted that Al Qaeda and its allies do not always function as a cohesive unit. And another cautioned, "There may be a division, but you haven't won anyone over to your side." The official spoke on condition his name not be used because of the sensitive topic.

Abu Farraj al-Libbi (search), the Libyan and top Al Qaeda operative, was captured in the northwestern part of Pakistan on May 2 after a fierce gunbattle. Now in Pakistani custody, he's accused of planning two assassination attempts on President Gen. Pervez Musharraf (search).

Al-Libbi used Pakistanis, not Central Asians, to carry out the December 2003 attacks on Musharraf — a sign of who he trusted, authorities said. And al-Libbi sent a Pakistani suicide bomber, they said, to try to kill the prime minister in 2004.

An agent in Pakistan's Inter-Services Intelligence (search), the country's equivalent of the CIA, said tensions with the Central Asians began building in late 2001, when hundreds of Arab Al Qaeda militants — including possibly bin Laden — poured across the Afghan border into the Pakistani tribal areas of South and North Waziristan.

Hundreds of Central Asians who had fought alongside the Taliban (search) fled across the border, too, joining countrymen who had settled in Waziristan (search) in the 1980s Afghan war against the Soviets.

The official said many new arrivals took up residence in rambling mud-brick compounds run by the Al Qaeda-linked Islamic Movement of Uzbekistan (search), whose fighters also were hiding in the area. The Arabs settled in different towns in Waziristan, setting up training facilities in Shakai where they trained Pakistani recruits.

Many Central Asians had been living in the region for years without incident. But the flood of Arab Al Qaeda suspects brought unwanted attention and problems.

At the same time, the Islamic Movement of Uzbekistan was left rudderless. Its commander and co-founder, Juma Namangani (search), was reportedly killed in a U.S. bombing campaign in late 2001.

He was replaced by Tahir Yuldash, known as a political philosopher rather than a military leader, said Katzman of the Congressional Research Service.

"They didn't have a strong figure any more to articulate their interests," said Katzman, whose agency advises U.S. lawmakers. "They had to rely more on the Arab leaders of Al Qaeda."

The heat began to rise amid a Pakistani military crackdown that flushed many militants out of the region in 2003 and 2004.

The Uzbeks and other Central Asians found themselves competing with Arab members of Al Qaeda for hideouts and resources with Arabs having the political and economic advantage, Katzman said.

Adding to the tensions was a lack of trust by senior Al Qaeda figures in the Central Asian fighters, said a senior Pakistani Interior Ministry official.

Another Pakistani security agent said the Central Asians "were Al Qaeda's foot soldiers, but they were never promoted. They felt ignored. The Central Asians were not happy," he added. "Usama bin laden and [his Egyptian deputy] Ayman al-Zawahiri (search) only trusted Arabs."

Increasingly, the two sides began operating independently, often competing for the same money, weapons and dwindling areas of influence among the Pakistani tribesmen. Captured Uzbek, Chechen and Tajik fighters felt far more loyalty to Yuldash than to the Arab Al Qaeda men.

The Pakistani intelligence official said it was difficult to get captured Uzbeks to talk about Yuldash, "but it was a lot easier to grill them for clues about the Arabs and their possible hideouts. They felt far less loyalty."

Another possible motivation for cooperation among captured Central Asians is a fear of being turned over to their home countries, which also have cracked down on Islamic militants.

Information from captive Uzbeks and Chechens — as well as paid informants working with Pakistani and American intelligence — helped authorities carry out a devastating raid on Al Qaeda's training camp in Shakai in June 2004, Pakistani officials told AP.

That raid was a turning point, driving Al Qaeda militants from their hideouts and making them easier to find.

Several militants, including a nephew of Khalid Shaikh Mohammed (search) — the alleged Sept. 11 mastermind who was captured in March 2003 — were arrested in Karachi after the Shakai raid.

Ultimately, police seized Mohammed Naeem Noor Khan (search), a 25-year-old computer expert whose hard-drives held information about apparent plans to attack Heathrow Airport, financial sites in the United States and other targets.

Khan led authorities to Ahmed Khalfan Ghailani (search), a Tanzanian with a $25 million U.S. bounty on his head for his role in the deadly 1998 embassy bombings in Africa. Ghailani, a confidant of al-Libbi, was arrested July 25 after a gunbattle in eastern Pakistan.

Less is known about what led to al-Libbi's arrest.

The Interior Ministry official told AP al-Libbi narrowly escaped arrest in the northwestern city of Peshawar in August 2004, but that authorities never completely lost his trail.

An intercept by U.S. agents of a cell phone call made by al-Libbi reportedly helped Pakistani agents track him down. They lay in wait — some disguised in women's all-encompassing burqas — then pounced as he and a colleague drove by motorcycle across a cemetery in Mardan.

Pakistani security agents say they're confident they have broken Al Qaeda's back, although bin Laden and al-Zawahri remain at large.

"Al Qaeda is no longer intact in Pakistan as a network," said Gen. Shaukat Sultan, the chief army spokesman. "Every organization needs a command structure and communication, and we have effectively destroyed both of them."