The American military has dismissed a claim by the al-Qaeda network that it has emerged largely unscathed from the US-led campaign in Afghanistan.

We have had a significant impact on (al-Qaeda's) ability to perform, command and control

US Army Colonel Roger King

US Army Colonel Roger King said the claim by Osama Bin Laden's organisation was "wishful thinking".

He was responding to a statement by a senior al-Qaeda official, Sulaiman Abu Ghaith, who said 98% of the group's leaders - including Bin Laden - were alive.

In the statement, broadcast by the Arabic al-Jazeera television channel on Sunday, Mr Abu Ghaith also said al-Qaeda was behind a suicide attack at a Tunisian synagogue in April, in which 19 people died.

Hunt

Colonel King, however, questioned the ability of al-Qaeda to operate.

"We felt that we have had a significant impact on their ability to perform, command and control," he said.

Sulaiman Abu Ghaith told the US to expect more attacks

"I feel if someone from al-Qaeda says that 98% of their command and control is still effective, it's wishful thinking on their part."

He was speaking at Bagram airbase outside Kabul - the centre of operations for thousands of US-led troops who have been scouring Afghanistan for remnants of al-Qaeda and Taleban forces, following last year's air and ground offensive.

The US-led force in Afghanistan has had little contact in recent weeks with Taleban or al-Qaeda fighters, many of whom are believed to have crossed into Pakistan.

But troops have uncovered weapons caches which they believe belonged to the militants.

In the audio tape broadcast by al-Jazeera, Mr Abu Ghaith praised the 11 September attacks on America and warned of similar actions "in the coming days and months".

Fuel tanker

Mr Abu Ghaith said the 11 April synagogue attack in Tunisia "was carried out by al-Qaeda network".

"A youth could not see his brothers in Palestine butchered and murdered... [while] he saw Jews cavorting in Djerba," he said.

The blast, which killed 14 German tourists, a French citizen and four Tunisians, happened when a fuel tanker blew up outside the ancient synagogue.

Most of the victims of the Djerba attack were tourists

The German Government said it suspected al-Qaeda of involvement in the attack.

Mr Abu Ghaith said the world would find out that Bin Laden was "in good health" in an interview which would be broadcast on television, although he did not say when.

He also denied reports that Bin Laden's deputy, Ayman al-Zawahri, was injured in a US bombing raid in Tora Bora, in eastern Afghanistan.

"As long as America insists on its unjust and biased policy towards Muslims in favour of Jews and Christians around the world, then... we will continue to hit it anywhere in the world."

He said that "neither [US Vice President] Dick Cheney nor Defence Secretary [Donald Rumsfeld] nor their president [George Bush] will be able to specify the place, the time or the manner in which these attacks will be carried out".

Al-Jazeera, a Qatar-based station, said it received the audiotape on Saturday, but it was not clear when or how it was obtained.

The station said the tape was recorded recently because it referred to claims last month that the US had information before 11 September that attacks were being planned.