Pakistani security forces critically wounded a top figure in the Taliban militia fighting U.S. and NATO forces in Afghanistan, one of six militants captured after a clash near the border Monday, the army said.

Mansoor Dadullah, brother of slain Taliban military commander Mullah Dadullah, and the five others were challenged by security forces as they crossed from Afghanistan into Pakistan's southwestern province of Baluchistan. They refused to stop and opened fire, said army spokesman Maj. Gen. Athar Abbas.

"Security personnel returned fire. As a result, all of them sustained injuries and all of them were captured," Abbas said. "Dadullah was arrested alive but he is critically wounded."

Earlier, a senior military official, speaking on condition of anonymity because he was not authorized to speak to journalists, said Dadullah died of his wounds while being flown to a hospital with the other injured men.

Two Pakistani intelligence officials, who declined to be named for the same reason, gave a different account of Dadullah's capture, saying he was nabbed during a raid on a religious seminary in a neighboring district. It was not immediately possible to reconcile the differing accounts.

Dadullah's capture comes amid growing Western pressure on Pakistan to crack down on Islamic militants launching attacks inside Afghanistan but increasingly destabilizing Pakistan itself.

In Afghanistan, officials reacted cautiously. Spokesmen at Afghanistan's Interior and Defense ministries said they had no immediate comment. Lt. Col. David Accetta, the top U.S. military spokesman in Afghanistan, said he could not confirm the report.

Dadullah rose in the militia's ranks as an important commander in southern Afghanistan after his brother was killed during a military operation in Afghanistan's Helmand province in May. Mullah Dadullah was the highest-ranking Taliban commander killed since the U.S.-led invasion of Afghanistan in 2001.

But in late December, Taliban spokesman Zabiullah Mujahid announced that Mansoor Dadullah had been dismissed from the movement for "disobeying orders" and conducting activities "against the Taliban's rules and regulations."

On Monday, Mujahid said Dadullah was still part of the Taliban movement, but that he was no longer an operational commander in southern Afghanistan.

Mujahid said he had no comment to make about Dadullah's reported capture.

Dadullah told the AP in a phone interview in January that he remained a Taliban commander and had asked the militia's supreme leader, Mullah Omar, to dispel "rumors" of his dismissal.

He also claimed that he had met with Al Qaeda's No. 2 leader, Ayman al-Zawahri, a few months ago but had never met with Osama bin Laden. He said Taliban and Al Qaeda fighters in Helmand were fighting alongside each other and sharing tactics.

Abbas, the army spokesman, said Dadullah was captured near Gaddal, a border village in Qila Saifullah district in Baluchistan.

Two Pakistani intelligence officials, however, gave the location as Gwal Ismailzai village, in neighboring Zhob district. They said five militants, not six, were captured and wounded, some critically.

One of the officials identified those captured with Dadullah on Monday as Haji Lala, Khudai Dad, Khaliq Dad and Abdur Razzak. He said the injured suspects were whisked away by an army helicopter from Zhob airport to an unknown destination.

Afghan and Western officials say that Pakistan's border regions are a staging point for cross-border attacks on U.S., NATO and Afghan forces inside eastern and southern Afghanistan. Dadullah is the latest in a series of high-ranking Taliban militants to have been killed or captured either side of the border in the past year or so.

Pakistan, a key U.S. ally in its war on terrorism, concedes Taliban militants are active on its soil but has denied Omar and other militia leaders use Pakistan as a base of operations.

In July 2007, another prominent militant, Abdullah Mehsud, died in Zhob, apparently after he was cornered by Pakistani security forces. Mehsud was a Taliban veteran of Guantanamo Bay who began fighting Pakistani security forces after his release from the U.S. prison for terror suspects in 2004.

In March 2007, two months before Mullah Dadullah was killed in Helmand, Mullah Obaidullah Akhund, one of the two top deputies of Taliban supreme leader Omar, was arrested in Quetta — where Afghan officials claim Omar is hiding.

In December 2006, another top Omar lieutenant, Mullah Akhtar Mohammad Osmani, died in a NATO airstrike in Helmand, near the Pakistan border.

Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, held talks over the weekend with President Pervez Musharraf and Pakistani military chiefs, and told reporters that the militant threat in the country's border regions was growing but ruled out violating Pakistan's sovereignty by sending U.S. forces to fight there.