The United Nations expelled three Jewish and Iranian groups from a global racism conference for what it called unacceptable behavior connected with the appearance of Iranian President Mahmoud Ahmadinejad. The groups whose passes are being withdrawn are the French Union of Jewish Students, Coexist, and the Neda Institute for Political and Scientific Research, said UN human rights spokesman Rupert Colville. Colville told reporters Thursday that members of the first two groups had been involved Monday in disrupting Ahmadinejad's speech, which was largely an attack on Israel. He did not elaborate, but a pair of rainbow-wigged protesters threw clown noses at Iran's president while others shouted "You are a racist!" and "Shame! shame!" from the gallery. Iranian spectators also cheered loudly. Later about 100 members of pro-Israel and Jewish groups tried to block Ahmadinejad's entrance to a news conference. The Neda Institute from Iran distributed inflammatory material to meeting participants, Colville said. He gave no details about the material from the pro-government Iranian group. The weeklong conference has been overshadowed by Ahmadinejad's accusation that the West used the Holocaust as a "pretext" to harm the Palestinians, and for subsequent protests against him. Late Wednesday, Iran sent a letter of protest to UN Secretary-General Ban Ki-moon for criticizing Ahmadinejad's speech. The Iranian president "was subjected to unfair and unwarranted harsh criticism," said Iran's ambassador to the UN in New York, Mohammad Khazaee, in the letter. The UN Office in Geneva was unable to comment on the letter early Thursday because it had not received it. Ban said Monday he deplored "the use of this platform by the Iranian president to accuse, divide and even incite. This is the opposite of what this conference seeks to achieve." "It is deeply regrettable that my plea to look to the future of unity was not heeded by the Iranian president," Ban said in a statement, adding that he met with Ahmadinejad before the UN conference stressing the importance of uniting in the fight against racism. Ban's comment was a response to Ahmadinejad's denunciation of Israel on the first day of the conference in Geneva, calling it the most "cruel and repressive racist regime." That sparked a walkout by European delegates, and strong condemnations from the UN, US and several other Western countries. Iran's ambassador noted that tolerance and freedom of expression were among the basic principles of the world racism conference. "It is unacceptable, and indeed regrettable, that these very principles were utterly disregarded in the same conference where we witnessed a manifestation of intolerance by some," he said. Khazaee said the UN secretary-general should be impartial and fair, adding that the majority of UN member states were concerned about the plight of the Palestinians, which he said were caused by Israel's policies and practices.