Ayman al-Zawahiri, al-Qaeda's second-in-command, has purportedly condemned Arab leaders who attended the recent US-sponsored Middle East conference in the US city of Annapolis.

In an audiotape posted on the internet, a voice said to be that of al-Zawahiri labelled the talks a "betrayal" to Palestinians.

Al-Zawahiri said: "The Annapolis meeting was held to turn Palestine into a Jewish state."

"The tsar of Washington, the crusader, brought together 16 Arab countries and their paralysed league [as well as] Amr Moussa, the secretary-general, to sit at a table with the Israelis."

He also denounced the government of Hosni Mubarak, the president of Egypt, saying he had turned the country into a "base to supply the crusader war on Muslims and Islam".

The message was the 15th tape or video released by al-Zawahiri this year, following an audiotape released in November in which he criticised Muammar Gaddafi, the Libyan leader, and announced that fighters in Libya were joining ranks with al-Qaeda.

However, the latest 20-minute statement has not been independently verified.