Osama bin Laden added his voice to the birthday messages accompanying Israel's 60th anniversary, vowing to fight on in the name of the Palestinian cause which he said was of primary concern to all Muslims.

As President Bush left Israel's anniversary celebrations with effusive pledges of US support for the Jewish state, the al-Qaeda leader chipped in with own analysis of the intractable conflict, saying it was one of the principle reasons he had turned to jihad as a young man.

“To Western nations ... this speech is to understand the core reason of the war between our civilisation and your civilisations. I mean the Palestinian cause,” said Bin Laden in a message that lasted almost ten minutes. “The Palestinian cause is the major issue for my nation. It was an important element in fuelling me from the beginning and the 19 others with a great motive to fight for those subjected to injustice and the oppressed,” he said, referring to the terrorists who hijacked four passenger aircraft in September 2001 to attack Washington and New York.

“Sixty years ago, the Israeli state didn't exist. Instead, it was established on the land of Palestine raped by force,” Bin Laden said. “Israelis are occupying invaders whom we should fight.” He is thought to be hiding out in tribal lands on the Pakistan-Afghan border.

Most Palestinians have rejected Bin Laden's claims to be fighting in their name, insisting that while al-Qaeda is killing people to recreate the medieval Caliphate, the vast Muslim empire that finally collapsed with the fall of the Ottomans at the end of the First World War, they simply want a homeland.

Mahmoud Abbas, the Palestinian President currently negotiating peace talks with Israel, recently gave warning that al-Qaeda was moving into the Gaza Strip, which is run by his rivals Hamas. The Islamist movement swiftly denied the claim and insists it has no links to al-Qaeda.

Bin Laden, who has claimed in the past to be fighting on the Palestinians' behalf, said the struggle would not stop. “We will continue, God permitting, the fight against the Israelis and their allies ... and will not give up a single inch of Palestine as long as there is one true Muslim on Earth,” he said in the message, his third this year, posted on an Islamist website.

The al-Qaeda leader said the Western media had spent decades brainwashing people by “portraying the Jewish invaders, the occupiers of our land, as the victims while it portrayed us as the terrorists”.

Times Recommends

• Both sides blame US for worsening relations
• Stieg Larsson: losing the plot over his cash
• Odd creature paralysed by incompatible parts