KABUL, Afghanistan -- Afghan officials and Taliban in hiding expressed no surprise Wednesday when they heard that an audiotape has surfaced purporting to be the voice of Osama bin Laden.

Many said they believed all along that the al-Qaida leader was alive -- perhaps in the semi-autonomous region across the border in Pakistan or in one of Pakistan's cities.

Some went so far as to suggest bin Laden is not only alive but traveling with Mullah Mohammed Omar, the deposed Taliban leader also wanted by the United States.

"I can say with full confidence that they are still active and are launching anti-government and anti-U.S. activities," said Gen. Said Agha, Afghan commander of the border security forces in eastern Nangarhar province.

According to a former Taliban diplomat, both men met recently with Mullah Akhtar Mohammed Usmani, a Taliban commander reputedly named by Omar as his successor. Usmani reported back that the two were safe, the source said.

"May God keep them safe and sound and curse those people who want to kill these leaders," said the diplomat, who asked that his name and location not be identified.

Bin Laden, the prime suspect in the Sept. 11 attacks on the United States, went into hiding shortly afterward. The audiotape appears to be the first hard evidence in nearly a year that the al-Qaida leader survived the U.S. airstrikes in Afghanistan. It surfaced Tuesday on Al-Jazeera, the Arab TV station based in Qatar.

On Wednesday, a U.S. official familiar with the tape said the audiotape was probably authentic.

'Could hide for years'

Agha, the Afghan commander, said it's possible bin Laden is traveling with Mullah Omar. The mountain peaks that run like a spine between Pakistan and Afghanistan would be a perfect hiding place for the two men, he said.

"They could be together. They disappeared about the same time. There are mountains here where they could hide for years," he said.

Others say they suspect bin Laden is in Pakistan, either in the tribal belt along the border or in a large city like Karachi.

"I'm not sure where he is. But in my thinking, he has more support in Pakistan, not in Afghanistan," said Noorullah Uloomi, a retired Afghan general who is helping to cobble together a national army.

Western intelligence sources say bin Laden's al-Qaida network is aligned with certain Islamic groups in Pakistan, including Harakat-ul Mujahedeen and Jaish-e-Mohammed, both banned in the aftermath of last year's attacks.

The groups' leaders were regular visitors to Afghanistan during the Taliban regime, said former Taliban Mullah Mohammed Khaksar, who abandoned the religious movement to support the U.S.-backed administration that now runs Afghanistan.

Retired Pakistani Gen. Sher Khan earlier said bin Laden's al-Qaida network is united with Pakistani militants in their hatred of the United States. They are further helped by elements within Pakistan's intelligence community, say other Taliban in hiding, who told The Associated Press that there is a division within Pakistan's spy agency -- those with the militants and those who support Pakistani President Pervez Musharraf and the war on terror.

The two top al-Qaida men in U.S. custody -- Abu Zubaydah and Ramzi Binalshibh -- were arrested in Pakistan. Zubaydah is considered the terrorist organization's No. 3 leader, and Binalshibh is one of the planners of the Sept. 11 attacks.

While the new tape may be a revelation for Western intelligence agencies, few Afghans ever subscribed to the theory that bin Laden had died either of poor health or from U.S. bombs.

"I am 100 percent confident that Osama bin Laden is alive," said Haji Mohammed Zaman, who fought alongside U.S. special forces in December in the mountains of Tora Bora near the Pakistan border.

Previously, U.S. intelligence said the last compelling evidence of bin Laden's whereabouts put him in Tora Bora. It's not clear whether he was there during the massive U.S. bombing campaign in December or stopped there en route to the southern city of Kandahar after fleeing Kabul in November.