The biggest protests were in the Yemeni capital Sanaa, where at least two demonstrators were killed in clashes, and in the Palestinian territories. Equally fiery rallies in support of Iraqi President Saddam Hussein were held in Bahrain, Egypt, Jordan, Lebanon, Sudan, Syria and in the West Bank.

Tens of thousands of angry demonstrators marched on the US embassy in Sanaa, chanting slogans against the United States, Israel, and Arab leaders as US and British forces continued their advance into Iraq.

"Leave office and open the door to Jihad!" they shouted, calling for Arab governments to let them fight a holy war alongside Iraqi forces. "Death to America! Death to Israel!"

The Yemeni interior ministry said two demonstrators were killed in clashes with police, and 23 people, including 14 policemen, hurt. But police said earlier that three protestors and a policeman were killed, adding that some protestors were armed.

In the West Bank and Gaza Strip almost 30,000 Palestinians took to the streets many calling on Saddam to bomb Tel Aviv. In the Gaza Strip, 15,000 people protested in the refugee camps of Jabalya, Rafah and Khan Yunis while an Imam in Gaza City called for the "opening of the borders" for Arab volunteers to go and fight with the Iraqi army.

In the West Bank city of Nablus, some 5,000 people marched through the streets after the Israeli army lifted the curfew for the day, chanting slogans such as "America, the mother of terrorism."

In occupied east Jerusalem Israeli police used tear gas and stun grenades to disperse some 300 Palestinians shouting their willingness to die for Saddam. In Ain El-Helweh around 2,000 protestors burned British, Israeli and US flags, while those of Germany and France, the leading Western opponents of the war, flew between the Iraqi and Palestinian flags.

Thousands of demonstrators clashed with security forces in the southern Jordanian town of Maan, an Islamist stronghold with a history of violent anti-government protests. Hundreds of people also took to the streets of the capital Amman and the northern city of Irbid, despite a government ban on unauthorized street rallies.

Police also used force in Cairo, where demonstrations moved to the city center after kicking off after Friday prayers at the historic Al-Azhar mosque. In central Cairo Qasr-el-Nil avenue clashes broke out when demonstrators hurled stones at anti-riot police, who responded with baton charges.

Anti-war activists said some 80 people were arrested, while witnesses said many of those detained were involved in the clashes and were hurt.

Earlier at Al-Azhar mosque, as many as 4,000 worshippers chanted "Down with America," "Allah Akbar (God is great)," and "Victory to Iraq", while some clambered onto the roof to hurl stones, shoes and rubbish at the security forces. Police said 10 people were injured in the clashes.

In Beirut, police clashed with some 1,000 students using water cannons to prevent them from marching on the US embassy. The demonstrators and police hurled stones at each other, and several people were seen being treated by members of the Red Cross for injuries.

In the Bahraini capital Manama a few hundred young demonstrators hurled stones at police forces that were protecting the US embassy.

Eleven of the soldiers were evacuated to field hospitals in the area, while the other two were treated at the scene.

"The carnage was pretty severe," said journalist Jim Lacey from Time magazine, who was at the camp at the time.

The BBC's Peter Hunt says Camp Pennsylvania occupies a large area of Kuwaiti desert and security should have been tight, so questions - potentially embarrassing ones - will now be asked about how this could have taken place.

The Associated Press news agency says the division has been based in Kuwait for about a week, but most of its personnel have already entered Iraq.

Correspondents say there are concerns in Kuwait about increasing hostility towards US troops, thousands of whom have been stationed in the country since the 1991 Gulf War.

In October last year, a US marine was killed during training on an island.

A month later, two US soldiers were shot and seriously wounded by a Kuwaiti policeman on a highway south of Kuwait City.