The opening of a United Nations conference in Switzerland on anti-racism was marred by chaotic scenes Monday as protests and a walkout by delegates disrupted a controversial address by Iranian President Mahmoud Ahmadinejad. The presence of the Iranian leader at the conference had already prompted Israel to withdraw its ambassador from Switzerland, while several countries including the United States are also boycotting the gathering. Dozens of delegates walked out of the chamber as Ahmadinejad accused Israel and the West of making "an entire nation homeless under the pretext of Jewish suffering ... in order to establish a totally racist government." Video Watch delegates make their exit » He said Zionism, the Jewish national movement, "personifies racism," and accused Zionists of wielding economic and political resources to silence opponents. He also blasted the United States-led invasion of Afghanistan. Protesters in brightly colored wigs interrupted Ahmadinejad as he began to speak, shouting: "You're a racist!" in accented English. But some delegates cheered, while security officers dragged at least two protesters from the chamber. Earlier, Israeli Prime Minister Benjamin Netanyahu and Foreign Minister Avigdor Lieberman called Ambassador Ilan Elgar home to protest a meeting between the Swiss president and Ahmadinejad, Israel's foreign ministry said in a statement. "The meeting of a president of a democratic country with a notorious Holocaust denier such as the Iranian president, who has openly declared his intention of wiping Israel off the map, is not in keeping with the values represented by Switzerland," the ministry said. Netanyahu's office had earlier said the diplomatic move was a response to the presence of Ahmadinejad at the conference. Ahmadinejad has said that the Holocaust is a myth, and Iran hosted a conference in 2006 questioning the Holocaust, in which about 6 million Jews were killed. The United States, among others, is refusing to send envoys to the Durban Review Conference. The U.N. high commissioner for human rights said Sunday that she regrets -- and is "shocked" by -- the United States' decision to boycott. "I am shocked and deeply disappointed by the United States' decision not to attend a conference that aims to combat racism, xenophobia, racial discrimination and other forms of intolerance worldwide," High Commissioner Navi Pillay said in a written statement. "A handful of states have permitted one or two issues to dominate their approach to this issue, allowing them to outweigh the concerns of numerous groups of people that suffer racism and similar forms of intolerance... These are truly global issues, and it is essential that they are discussed at a global level, however sensitive and difficult they may be," she said. The U.S. State Department said Washington's decision was based in part on a conference document that "singles out" Israel in its criticism and conflicts with the United States' "commitment to unfettered free speech." President Barack Obama noted Sunday that the United States had previously warned it would not attend the conference if the document was not sufficiently altered in advance. According to the State Department, the document contains language that "prejudges key issues that can only be resolved in negotiations between the Israelis and Palestinians." The language reaffirms the Durban Declaration and Programme of Actions from the 2001 conference in Durban, South Africa, which the United States has said it won't support. Obama said the United States hopes to partner with other countries "to actually reduce discrimination around the globe, but this (conference) wasn't an opportunity to do it." Australia, Canada, Germany and Italy, among others, are also boycotting the conference. Poland announced Monday it too would pull out of the conference. Netanyahu on Monday praised the countries that refused to attend: "I congratulate the nations that boycotted the show of hate." Show Less >>