The president is very concerned that an action was taken that was wrong and inappropriate, and the president apologises for it

White House spokesman

The whole group of visiting Muslim leaders then left in protest. When the Secret Service realised that it had made a mistake, the Muslims were invited back, but they declined.

"The president is very concerned that an action was taken that was wrong and inappropriate, and the president apologises for it on behalf of the White House," said White House spokesman Ari Fleischer.

Funding meeting

The Muslim leaders were at the Old Executive Office Building for a meeting to discuss President Bush's faith-based initiative, that calls for providing federal funds to religious organisations involved in charity and community work.

Mr al-Arian's uncle was imprisoned by the US

Ibrahim Hooper of the Council on American Islamic Relations welcomed Mr Bush's apology.

But he called for the White House to appoint a full-time liaison officer to the Muslim community, to "dispel impressions within the Muslim community that there's some kind of exclusion from his policy-making circles".

The BBC's Stephen Sackur in Washington says that there has still been no explanation as to why Mr al-Arian, a student doing volunteer work in Washington, should have been ejected.

But his uncle, a Palestinian academic, was imprisoned for three years without trial by the US authorities after being accused of links with Islamic militants. Mazen al-Najjar was released six months ago.