Bin Laden's Message From Beyond The Grave

Al Qaeda has released a posthumous audio tape of Osama bin Laden praising revolutions sweeping the Arab world and urging Muslims to rise up.

The 12-minute message posted on jihadist web forums included advice on how to spread revolt across the Islamic world.

Al Qaeda said bin Laden had recorded the tape a week before he was killed at his hideout in Pakistan.

In the audio, a voice reported to be bin Laden's lavishes praise on revolutions earlier this year in Tunisia and Egypt.

"Tunisia was the first but swiftly the knights of Egypt have taken a spark from the free people of Tunisia to Tahrir Square," he said.

"It has made the rulers worried."

Meanwhile, America's defence chief has said Pakistan's leaders were unaware bin Laden had been hiding on their soil.

In a strong defence of officials in Islamabad, defence secretary Robert Gates said he believed "somebody knew" of the al Qaeda leader's whereabouts.

He added: "I have seen no evidence at all that the senior leadership knew.

"In fact, I've seen some evidence to the contrary."

He would not say who the "somebody" may have been, but suggested it could have been retired or low-level Pakistani officials.

Mr Gates' comments come after claims that leaders may have somehow helped harbour bin Laden before he was killed in a US special forces raid on his compound some 35 miles north of the capital.

Mr Gates and the Joint Chiefs of Staff chairman, Admiral Mike Mullen, said in a news conference that both countries must continue to work together - and that Islamabad must take concrete action to eliminate militants' havens along the border with Afghanistan.

Pakistani Taliban have vowed to fight with "new zeal" to complete the al Qaeda chief's mission of waging holy war against the West.

Adm Mullen has forged a close relationship with his Pakistani counterparts, encouraging them to move against high-level terrorists known to be hiding in Pakistan, including al Qaeda's number two leader, Ayman al Zawahri.

But diplomatic relations have been damaged by the US raid on bin Laden's hideout, which Pakistan's government was not warned about.