An audio tape said to be by al-Qaeda deputy leader Ayman al-Zawahiri has been posted on a website - a week after an alleged US air strike targeting him.

The speaker praises Islamic fighters in Afghanistan but does not mention the strike - on a Pakistani village.

The posting came a day after Arabic TV station al-Jazeera broadcast a message thought to be from Osama Bin Laden.

It is the first time Bin Laden has been heard from since December 2004.

A CIA spokesperson said in Washington of the latest posting: "Following technical analysis of the tape, the CIA has assessed that it is the voice of Ayman al-Zawahiri."

The 18-minute tape takes the form of a long poem praising the "martyrs" fighting Western forces in Afghanistan.

Meanwhile, several thousand people joined an anti-US rally in the Pakistani city of Peshawar on Friday in protest at the missile strike, in which 18 people died.

The attack took place in Damadola village, in the Pakistani tribal area bordering Afghanistan.

Zawahiri is not thought to have been present at the time of the raid but Pakistan says a number of foreign fighters were killed.

The US has about 20,000 troops in Afghanistan, but Islamabad does not allow them to operate across the border.

Pakistani Prime Minister Shaukat Aziz has said he intends to raise the issue with US President George W Bush when he meets him in Washington next week.

PHOTO CAPTION

Ayman al-Zawahiri giving a speech at undisclosed location. (AFP)