Saudi Arabia's top cleric called on Muslims around the world Saturday to forsake terrorism, saying those who claim to be holy warriors were an affront to the faith.

In a sermon that was remarkable not only for its strong language but also its timing — at the peak of the annual hajj — Sheik Abdul Aziz al-Sheik (search) told 2 million pilgrims that terrorists were giving their enemies an excuse to criticize Muslim nations.

"Is it holy war to shed Muslim blood? Is it holy war to shed the blood of non-Muslims given sanctuary in Muslim lands? Is it holy war to destroy the possession of Muslims," he said.

A large number of the victims of homicide attacks in Saudi Arabia, Turkey, Iraq and elsewhere have been been Muslims.

Al-Sheik, who is widely respected in the Arab world as the foremost cleric in the country considered the birthplace of Islam, spoke at Namira Mosque (search), a televised sermon watched by millions of Muslims in Saudi Arabia and other Gulf states.

The mosque is close to Mount Arafat (search), where the pilgrims converged Saturday for the climax of their annual trek. This year's hajj has been carried out amid heightened security after a year of terror attacks in the kingdom.

In speaking of terrorists who killed fellow Muslims, al-Sheik was clearly referring to the Prophet Muhammad's final sermon, delivered on Mount Arafat 14 centuries ago.

It contained the line: "Know that every Muslim is a Muslim's brother, and the Muslims are bretheren. Fighting between them should be avoided."

Al-Sheik also criticized the international community, accusing it of attacking Wahhabism (search), the sect whose strict interpretation of Islam is followed in Saudi Arabia.

"This country is based on this religion and will remain steadfast on it," he said.

"Islam forbids all forms of injustice, killing without just cause, treachery ... hijacking of planes, boats and transportation means," he said.

Saudi Arabia came under Western pressure after the Sept. 11 attacks on the United States, in which 15 of the 19 hijackers were Saudi citizens.

The Saudi government conducted a crackdown on extremist groups after homicide bombers attacked housing compounds inhabited by foreigners last May. Saudi and U.S. officials blamed the attack, and a similar homicide bombing in November, on groups linked to Al Qaeda (search), which is led by the Saudi-born Usama bin Laden.

On Thursday, suspected terrorists shot dead six Saudi security personnel in a shootout in a house in suburban Riyadh.

All total last year, bombings in Saudi Arabia killed 51 people, including eight Americans. Saudi and U.S. officials have blamed bin Laden's Al Qaeda network. Bin Laden is a Saudi exile.

The United States has pushed the Riyadh government to crack down on Muslim extremist groups and to censor its mosque sermons and school books to eliminate phrases that encourage hostility toward Christians, Jews and other non-Muslim faiths.

Liberal intellectuals in Saudi Arabia and Kuwait also called for such revisions in the teaching of Islam in schools and mosques.

Governments in Saudi Arabia, Kuwait and Jordan have taken steps toward purging school books of terms offensive to other religions, and reformers argue that change should start by lessening the religious grip on education.

Al-Sheik warned against "changing the religion's basics" in school curricula.

"The minds of youth in the Islamic nation need to be shielded with Islamic sharia and good manners and deeds. The nation's future generations will only be reformed by what reformed the past generations," he said.

The pilgrims arrived at Mount Arafat in the early hours of Saturday. Worshippers of all ages and origins, moving slowly, shoulder-to-shoulder, shaded themselves from the sun with white umbrellas, chanting in unison "at thy service, at thy service, oh God."

Emergency workers directed the crowd as it converged 12 miles southwest of Mecca, in a ritual believed to represent the Day of Judgment, when Islam says every person will stand before Allah, or God, and answer for his deeds.

"Oh my God, oh my God, we are actually here. There is nothing better than responding to God's call and being here," said Zainab Menaid, a Tunisian pilgrim.

Temperatures approached 86 degrees. The sunshine made parasols a popular purchase at $1.30 each, and street vendors sold fruit, prayer mats and drinks. Along the path to Mount Arafat, sprinklers mounted on poles cooled worshippers. Free water and milk were handed out.

"I could not wait to reach here. This is primarily what we came for," said Egyptian Abdel Aziz al-Jezairi. "This is the worst day for the devil. When he sees thousands of Muslims gathered in such a show of force and piety."

Fatima Farouk, a Nigerian who was performing the hajj for the first time, said that despite the demanding journey, she was thrilled "because after Mount Arafat, you're almost promised heaven."