Mullah Obaidullah Akhund, who ranks third in the Taliban's 10-member leadership council, was picked up in a covert operation Monday, the Pakistani newspaper Dawn and international dailies reported, citing security sources.

But there was no direct confirmation from top military or interior ministry authorities.

Nine Afghan and Pakistani suspects were arrested in two separate raids in Quetta on Monday, the city's police chief Rao Ahmed Khan told dpa. But he said Obaidullah Akhund was not among them.

Khan said the nine were taken in as part of "a regular exercise of hotel checking" to detain illegal persons and suspects.

Quetta is the capital of the province of Balochistan and is located 60 kilometres from the border with Afghanistan. Taliban elements near the border are thought to recruit many fighters from local camps for Afghan refugees.

Meanwhile, a Taliban spokesman, Qari Mohammad Yusuf told dpa by telephone that the reports were baseless. He claimed to have spoken himself with close associates of Obaidullah Akhund Friday, and that "they said he was well."

He and the rest of the Taliban leadership were in Afghanistan continuing operations, he added.

Mullah Obaidullah was the former defence minister of the Taliban before the radical Islamist militia was ousted from power in Afghanistan by US-led forces in 2001. He is also a religious scholar and was educated in madrassa in two Pakistani cities.

Soon after the fall of the Taliban he surrendered to the Afghan government but was quickly released under an amnesty deal.

Fellow commanders have since died in clashes with international forces in Afghanistan. But his reported capture could deal an unprecedented blow to the Taliban's top circle and potentially disrupt preparations for upcoming militant operations.

The Taliban claims it has at least 6,000 fighters and 2,000 suicide bombers ready for an imminent broad offensive.

US and NATO-led coalition forces numbering more than 45,000 have also threatened to launch pre-emptive strikes against insurgents in the south and east of Afghanistan.

The reported arrest Monday coincided with an unannounced visit to Islamabad by US Vice President Dick Cheney to call for greater Pakistani efforts against Taliban and al-Qaeda elements.

But reports said the arrest was planned in advance using intelligence inputs and there was no link to the US official's visits.

A militant commander in Afghanistan's southern Zabul province and the former Taliban governor of Helmand province were also thought to have been arrested, according to Dawn.

Meanwhile, US-led coalition forces in Afghanistan said a "known terrorist" and seven suspects were detained Friday in the Paktika province by the border with Pakistan.

The International Security Assistance Force (ISAF) in Afghanistan also said that 12 Taliban fighters died in a clash Tuesday. One ISAF soldier was injured in the attack, which involved coalition air strikes.