US intelligence authorities have informed the White House that the audiotape attributed to al-Qaida leader Osama bin Laden was authentic, White House spokesman Scott McClellan said on Sunday.

"The al-Qaida leadership is on the run and under a lot of pressure," McClellan said at a Marine base in Twenty-nine Palms, California, where Bush was having lunch with military families.

"We are on the advance. They are on the run," he said.

The remarks were made in response to bin Laden's new threats on an audiotape broadcast on the pan-Arab television al-Jazeera, in which he accused the United States and Europe of supporting a "Zionist" war on Islam by cutting off funds to the Hamas-led Palestinian government.

In the tape, bin Laden also urged followers to go to Sudan, his former base, to fight a proposed UN peacekeeping force.

It was the first message by the al-Qaida leader for three months. The voice on the tape sounded strong and resembled that on other recordings attributed to bin Laden.

Reports here said al-Jazeera appeared to have had the tape long enough to make significant edits, with its news reader providing background comments. The network broadcast about five minutes of the tape in all.

In Washington, US intelligence officials said bin Laden was living separately from his lieutenant Ayman al-Zawahri.

The al-Qaida chieftain, who last issued a message broadcast by al-Jazeera on January 19, also made a point of trying to justify attacks on civilians.

He said citizens of Western countries were equally responsible with their governments for what he termed the "war on Islam."

(Xinhua News Agency April 24, 2006)