Excerpts from a recording published on Islamist websites believed to have been recorded by Osama bin Laden Reuters

A tape recorded by Osama bin Laden before his death in a US special forces raid earlier this month has been released posthumously onto Islamist militant websites.

The message, recorded some time in the 10 weeks before the 54-year-old al-Qaida leader was killed in Pakistan on 2 May, praises the Arab spring protest movements across the Middle East and predicts that revolutions will spread.

"I think that the winds of change will blow over the entire Muslim world, God willing," Bin Laden said in the 12-minute clip.

The video message contains only an audio track and an old photo of the terrorist leader, probably indicating it was designed to be edited with images but that al-Qaida media technicians were either unable to do so or that a decision was taken to upload the tape quickly.

The senior al-Qaida leadership was caught out by the unrest in the Arab World this spring and had difficulty framing an effective response to an outpouring of enthusiasm for democracy and pluralism.

In deposing President Hosni Mubarak in Egypt and Zine al-Abidine Ben Ali in Tunisia, protesters achieved fundamental aims of al-Qaida without violence.

In the recording, Bin Laden accused rulers in the Middle East of building themselves into idols and manipulating the media to stay in power.

Al-Qaida figures have frequently blamed the media for the failure of the majority of Muslims to heed its call to arms.

"So, what are you waiting for?" Bin Laden asked in the most recent tape. "Save yourselves and your children, because the opportunity is here."

Bin Laden, who is thought to have been living in a three-storey house in the northern Pakistani town of Abbottabad for up to five years, spoke in highly rhetorical language and avoided the more violent or apocalyptic language of many previous statements.

A full transcript of the tape is yet to be made available but Bin Laden appears not to have threatened the west directly as has previously often been the case.

"Let the truth ring out," he told listeners. "Remember those that go out with a sword are true believers, those that go fight with their tongue are true believers, and those that fight in their hearts are true believers."

He said "the sun of the revolution has risen from the Maghreb".

"The light of the revolution came from Tunisia. It has given the nation tranquillity and made the faces of the people happy," al-Jazeera, the Qatar-based TV channel reported Bin Laden saying in the tape.

Bin Laden's close associate, the Egyptian Ayman al-Zawahiri, has already issued statements about the unrest as has senior figures in al-Qaida affiliate groups, such as that based in the Yemen.

In the internet-published magazine Inspire, extremists welcomed the uprisings as opening the door to radical Islam.

Bin Laden attributed to problems of the region to "ignorance of Islam" and said the revolts had "made the rulers worried".

"Tunisia was the first but swiftly the knights of Egypt have taken a spark from the free people of Tunisia to Tahrir Square. This wasn't a revolution of starving and pain, but a revolution of giving and peace," the Saudi-born fugitive said.

Bin Laden called on followers to act immediately: "A delay may cause the opportunity to be lost, and carrying it out before the right time will increase the number of casualties."

The recording was widely expected. It was released to jihadist websites by al-Qaida's media arm, al-Sahab.

Scores of recordings were found in the home in Abbottabad where Bin Laden lived.

President Barack Obama is to make a major speech on the Middle East on Thursday.