Media playback is unsupported on your device Media caption In the audio message, Bin Laden praises the revolutions in Tunisia and Egypt

A recording purported to have been made by Osama Bin Laden shortly before he died has been released by al-Qaeda.

In the message, he praises the revolutions in Tunisia and Egypt and speaks of a "rare historic opportunity" for Muslims to rise up.

The 12-minute audio message appeared on a video posted on Islamist websites, and has been translated by the US monitoring group SITE intelligence.

Bin Laden was shot dead by US Navy Seals at a Pakistan compound on 2 May.

Speculation is mounting that al-Qaeda has appointed a former Egyptian army colonel, Saif al-Adel, as temporary leader to replace Bin Laden.

Adel was once Bin Laden's security chief, and is suspected of involvement in the 1998 US embassy bombings in East Africa, training the Somali fighters who killed 18 US servicemen in Mogadishu in 1993, and instructing some of the 11 September 2001 hijackers.

He fled to Iran from Afghanistan after the US-led invasion in 2001, and was reportedly held under house arrest near Tehran. Reports at the end of last year said he may have been released and made his way to northern Pakistan.

Some Western analysts have expressed scepticism over reports of his appointment. Bin Laden's long-time deputy Ayman al-Zawahiri, also Egyptian, is thought to be the front-runner for the role.

'Serious crossroads'

In the recording, Bin Laden refers to the revolutions in Tunisia and Egypt but makes no mention of the uprisings in Syria, Libya and Yemen.

"I think that the winds of change will blow over the entire Muslim world, with permission from Allah," he says.

"There is a serious crossroads before you, and a great and rare historic opportunity to rise up with the Ummah (Muslim community) and to free yourselves from servitude to the desires of the rulers, man-made law, and Western dominance," he also says.

"So, what are you waiting for? Save yourselves and your children, because the opportunity is here".

Al-Qaeda is generally perceived to have been caught off guard by the Arab Spring uprisings that began in January in Tunisia and swiftly followed in Egypt - toppling the long-time leaders of both countries.

Analysts say that while both al-Qaeda and the West back the uprisings sweeping across several Arab nations, they seek very different outcomes. The West hopes they will lead to democratic reforms, while al-Qaeda wants to see new governments based on their interpretation of Islamic law.