In the recording, aired by Aljazeera on Sunday, the al-Qaeda leader said the isolation and denial of aid to the Hamas-led Palestinian government is one such case.

"The blockade which the West is imposing on the government of Hamas proves that there is a Zionist crusader war on Islam," he said. It is also not clear when the recording, believed by Washington to be authentic, was made.

Bin Laden also said the Western public shared responsibility for the actions of their governments, particularly for what he called their attacks on Islam.

"The war is a responsibility shared between the people and the governments," he said. "The war goes on and the people are renewing their allegiance to their rulers and masters.

"They send their sons to armies to fight us and they continue their financial and moral support while our countries are burned and our houses are bombed and our people are killed." 

US reaction

US intelligence agencies believe the latest tape is authentic, the White House said on Sunday.

After being informed of the intelligence assessment, White House spokesman Scott McClellan said in Twentynine Palms, California: "We are continuing to take all terrorist threats seriously and that is why we are acting on all fronts doing everything within our power to prevail in the war on terrorism.

"The al-Qaeda leadership is on the run and under a lot of  pressure. We are continuing to take the fight to the enemy abroad, and making it difficult for them to plan and plot against America." 

At other points in the message, bin Laden spoke about the conflict in Iraq and, for the first time, the crisis in Darfur, Sudan.

Bin Laden called on supporters to
fight in Darfur

He urged Muslim supporters to go to Sudan to foil what he called Western, especially American, efforts to divide the country.

"I call on mujahidin (fighters) and their supporters, especially in Sudan and the Arab peninsula, to prepare for long war against the crusader plunderers in Western Sudan.

"Our goal is not defending the Khartoum government but to defend Islam, its land and its people," he added.

He also denounced the January 2005 north-south peace accord, saying to "[Sudanese President] Omar al-Bashir and Bush that this agreement is not worth the ink it was written with and does not bind us".
 
Southern Sudan, he said, had to stay part of the "Islamic lands".

More than three years of conflict between tribal rebels and government-backed militias in Darfur has left about 300,000 people dead and forced more than two million people from their homes.

Commenting on the message, Dia Rashwan, an expert on Islamic groups at the Al Ahram Centre for Strategic Studies in Cairo, told Aljazeera the tape showed bin Laden returning as leader after a long absence and calling on his soldiers to go to the battlefield.

Cartoons

The al-Qaeda chief also called on Muslims to expand the boycott resulting from the publication of cartoons of the Prophet Muhammad in Danish newspapers.

"They send their sons to armies to fight us and they continue their financial and moral support while our countries are burned and our houses are bombed and our people are killed"

Osama bin Laden

He said action should be taken against the US and other European countries that have sided with Denmark on the issue.

Those that have wronged the prophet should be handed over to al-Qaeda for judgment, he said.

The cartoons, including one showing the prophet with a bomb-shaped turban, sparked violent protests by Muslims worldwide.
Muslims consider any image of the prophet to be blasphemous.

In other parts of the tape:

  • Bin Laden criticised the United Nations as a puppet of the West and a "heretical" organisation. The Security Council, he said, excluded Islamic nations and gave the right of veto to "the crusaders of the world and the Buddhist pagans".
  • He condemned Saudi Arabia's King Abdullah for what he said was the king's rejection of the idea of a clash of civilisations. In truth, he said, the West had launched an assault against the Islamic civilisation.

The last recorded message from bin Laden, was aired by Aljazeera on January 19.

In that message he threatened new attacks against the US, but also offered the American people a conditional "truce".

The last time the al-Qaeda leader was seen on camera was in a videotaped message released just prior to the US presidential elections in late 2004.