Pakistani security forces captured the former Taliban defense minister, Pakistani intelligence officials said Friday, in what would be the highest-ranking leader from the Afghan insurgency to be arrested since it lost power in 2001.

There was no immediate official confirmation from the Pakistani government about the arrest of Mullah Obaidullah Akhund, regarded as one of the two top deputies of Taliban supreme leader Mullah Omar. A Taliban spokesman dismissed the report as a "rumor."

Akhund was nabbed with four other suspects in a raid on a home in the southwestern city of Quetta on Monday, three intelligence officials said on condition of anonymity because they were not authorized to speak to journalists.

The arrests came amid growing international pressure on Pakistan to crackdown on Taliban militants and coincided with a visit to Islamabad on Monday by Vice President Dick Cheney.

During his visit, Cheney had expressed concern to President Gen. Pervez Musharraf over Al Qaeda regrouping inside Pakistan's tribal regions and an expected Taliban spring offensive in neighboring Afghanistan.

One of the intelligence officials said Akhund's arrest was a planned operation following a tip from U.S. officials and was not linked to Cheney's visit. He said that seven more Taliban suspects had been arrested, also in Quetta, later in the week. He had no information about the identities of the other suspects.

Brig. Javed Iqbal Cheema, a senior Interior Ministry official handling counterterrorism issues, denied late Thursday that a top Taliban figure had been arrested and was not answering calls Friday. Tariq Khosa, police chief of Baluchistan province where Quetta is located, said he was not aware of Akhund's arrest.

Afghan and NATO officials could not confirm the arrest either.

"To the best of my knowledge we were not involved in anything associated with him," Col. Tom Collins, the spokesman for the NATO's International Security Assistance Force, said in Kabul. "We were not involved in that operation."

Akhund's arrest was also reported by the New York Times and Pakistan's respected Dawn daily newspaper. Dawn cited an unnamed federal official, who was quoted as saying that two of the suspects captured with him "could be" Amir Khan Haqqani, a Taliban commander in Afghanistan's southern Zabul province, and Abdul Bari, the former Taliban governor of Helmand province.

Qari Yousuf Ahmadi, who claims to speak for the Taliban, denied Akhund had been captured.

"It's just a rumor," Ahmadi told The Associated Press by phone from an undisclosed location. "Mullah Obaidullah is in Afghanistan, he's not in Pakistan."

Ahmadi confirmed Akhund's stature inside the Taliban movement as one of Omar's two top lieutenants, along with Mullah Biradar. He said the two men had been appointed by Omar to command the militia's jihad, or holy war, inside Afghanistan.

Taliban-led militants have staged a resurgence over the past year, threatening the elected Afghan government of President Hamid Karzai. Bitter fighting with Afghan, NATO and U.S. forces during 2006 left thousands dead, and militant leaders are threatening a new wave of attacks as winter subsides in the coming weeks.

Gen. Mohammad Zahir Azimi, spokesman for the Afghan defense ministry, said Akhund's arrest, if confirmed, would affect the command and control system of the Taliban.

"He was a very important person in the Taliban movement," Azimi said. "It will be a big blow to Taliban morale."

The surge in violence, particularly in southern Afghanistan, has badly strained Pakistan's relations with Afghanistan, which claims the Taliban movement is commanded from Quetta. Karzai has claimed that Omar himself is staying in Quetta.

The presence of Taliban leaders in the southwestern city, which is heavily populated by Afghan migrants, is hard to substantiate. The clearest public sign, prior to Akhund's reported capture, was the arrest there in October 2005 of a Taliban spokesman, Latif Hakimi, who lived in the city with his family.

In recent months, NATO has reported a string of successes in killing or arresting Taliban commanders in Afghanistan: most significantly, Mullah Akhtar Mohammad Osmani — another top Omar lieutenant — who was killed in an airstrike in southern Helmand province, just across the border from Pakistan, in December.

Musharraf and U.S. officials have said that Pakistan — a former supporter of the Taliban regime but now a key ally of Washington in its war on terror — helped in the operation to eliminate Osmani, a top military commander for the insurgents in their southern Afghan heartland.

Speaking in early February, Musharraf also said another top militant commander, Mullah Dadullah, had been inside Pakistan three times but evaded capture. He didn't give details, but described it as a "a combined failure" of Pakistan and anti-terror allies who shared the intelligence.

In an interview with an Al-Jazeera TV journalist last week, Dadullah claimed he had deployed more than 6,000 fighters for a spring offensive. He said the fighters were hidden in tunnels and elsewhere in preparation the assault.