KANDAHAR, Afghanistan (AFP) -- The Taliban's former defense minister is leading a force of about 400 insurgents in a southern district where a major NATO-led offensive is underway, an Afghan general said Wednesday.

Mullah Ubaidullah Akhund has not been seen since shortly after the ultra-Islamist regime was toppled by U.S.-led forces in late 2001, although he purportedly issued a few brief statements in the intervening five years.

The Afghan army general, who is involved in Operation "Baaz Tsuka" (Falcon's Nest) in and around Panjwayi district in Kandahar province, said Ubaidullah was giving orders to Taliban fighters in the area.

"Mullah Ubaidullah is in charge of the Taliban forces in Panjwayi," the general told AFP on condition of anonymity. He cited intelligence reports and information from troops on the ground, as well as from captured insurgents.

The commander estimated there were about 400 Taliban fighters in the area, which is 30 kilometers (19 miles) south of Kandahar city, the birthplace of the movement that ruled most of Afghanistan from 1996 to 2001.

Some had stayed behind in Panjwayi after a major NATO-led International Security Assistance Force (ISAF) operation codenamed "Medusa" in September, during which the alliance said some 1,000 rebels were killed.

Faced with hundreds of ISAF and Afghan troops who poured back into the area last Friday, the Taliban fighters were now likely to withdraw to avoid casualties, the general said.

"We have intelligence reports that Taliban leaders told their men to pull out without fighting," he said. "The order to pull out came from Mullah Ubaidullah."

Reports after the invasion of Afghanistan said Ubaidullah was among several Taliban Cabinet ministers who surrendered to Northern Alliance forces but were later released.

Earlier this year he rejected an olive branch held out by Afghanistan's U.S.-backed President Hamid Karzai.

Meanwhile, the general said September's operation meant the rebels were "now too weak to fight another battle".

Ahead of operation Baaz Tsuka, ISAF troops air-dropped leaflets in Panjwayi, warning the rebels either to withdraw or face battles which would force them out.

Since the launch of the assault more than 30 Taliban fighters, including two rebel commanders, have been killed in two separate air strikes by ISAF on insurgent "command posts", the force has said.

But barring some small-scale gunfights, the troops have not faced any resistance in the area since entering the orchard-lined valley, an ISAF spokesman said.

The Afghan general said the militants were expected to pull back via neighboring Helmand province to hideouts across the border in southwest Pakistan.

Afghanistan has accused Pakistan of both fomenting the Taliban insurgency, which has claimed 4,000 lives this year, and failing to crack down on the cross-border movement of militants.

Pakistan has strongly denied the allegations and said it had launched a series of operations in its frontier regions in the past three years that have left more than 600 Pakistani soldiers dead.