"Three years after the invasion, this government has not learnt one lesson," said Robert Brown, a teacher from Oxford who came to the London Anti-war march with his family, reported Agence France-Presse (AFP). "You cannot build democracy with bombs," he asserted. John Rees, co-founder of Stop the War Coalition, agreed.

"We want to achieve two things: to hurry the British government into leaving Iraq and to make it aware of public opinion that it can't join the American government if it attacks Iran," he said.

According to police estimate, more than 14,000 anti-war protesters marched through London on Saturday, some holding placards of US President George W. Bush and the words "World's Number 1 Terrorist".

Others carried banners saying "Peace not Profit" and "End the occupation, don't attack Iran".

A handful of protesters donned orange boiler suits and wore shackles on their wrists to mimic outfits worn in the US Guantanamo Bay prison, and carried photographs of prisoners.

The demonstration was organized by the Campaign for Nuclear Disarmament, Stop the War Coalition and the Muslim Association of Britain.

Britain, which has 8,000 troops in Iraq, has linked withdrawal to the ability of local security forces to shoulder their responsibility in maintaining law and order.

Acting without a UN mandate, US-led forces invaded oil-rich Iraq in March 2003, under the pretext of imminent threat posed by the country's alleged weapons of mass destruction, none of which was ever found.

Representative

Chanting "Tony, Tony, Tony, out, out, out," and "George Bush we know you, your father was a killer too", marchers from across Britain wended their way from the Houses of Parliament, past Queen Elizabeth's London residence and on to Trafalgar Square.

Former left-wing Labour minister and veteran anti-war campaigner Tony Benn said the protest against the war was representative of public opinion worldwide.

"What's important is the people who have come on the march. We have built relationships with Muslims, Jews, Christians, blacks, whites," he told Reuters.

"We want to dismiss the idea that it's a religious war, which it isn't."

Mayor of London Ken Livingstone, who has opposed the invasion all along, also made an appearance at the event in Trafalgar Square.

According to a Populus poll conducted last month, 64 percent of Britons are against the Iraq war.

Rome

US citizens march in Rome to protest the invasion of Iraq. (Reuters)

Anti-war sentiment appeared to be the strongest in Rome where tens of thousands took to the streets, carrying signs "Stop the war in Iraq" and "No to the war for oil."

"Iraq is on the brink of civil war. This war must be stopped before it degenerates into a conflict of civilizations," said Fausto Bertinotti, head of the Refounded Communist Party (PRC), one of the leftist groups behind the demonstration.

The demonstration comes about three weeks before Italy's April 9-10 legislative elections.

The ruling center-right government of Prime Minister Silvio Berlusconi, a strong Bush ally, sent nearly 3,000 Italian soldiers to Iraq despite the objections of a majority of Italians.

In Athens, nearly 2,000 protestors marched to the US embassy, led by Palestinian immigrants who chanted anti-American slogans.

Protests were also held outside US facilities at Souda military base on the island of Crete and in Greece's second city of Salonika.

The latest opinion poll published in the Greek daily Kathimerini on Saturday showed that 85 percent of those surveyed considered the invasion of Iraq a mistake, compared with three percent who said it was "just".

Out Now

Protesting the Iraq invasions, Turks did not forget Guantanamo detainees. (Reuters)

Demonstrators in Istanbul, led by leftist and Islamist groups, also called for the American troops to pull out of Iraq.

Turkish public opinion has been nearly unanimous in opposing the US-led invasion of Iraq, a neighboring country.

The Turkish government had refused to allow the invading troops to pass through its territories, thereby preventing an opening of a second front in northern Iraq.

The withdrawal call was echoed at a small demonstration in Nicosia on the Mediterranean island of Cyprus, an EU member.

"We call for the withdrawal of American troops from Iraq. At the same time, we demand that those who created the problems resolve them," said Andros Kyprianou, a spokesman for the Akel communist party, the biggest party in the Chypriot parliament.

Mohammad Ahmad, a 30-year-old Iraqi asylum seeker, said it was time for the Americans to leave his homeland "but not before speeding up the formation of the government and security forces," he said.

In Copenhagen, some 3,000 people took to the streets, organizers and police said, with banners reading "Bring back the troops now".

Demonstrators rallied outside the US embassy before marching on to the British embassy.

In Stockholm where a few hundred people braved the cold and falling hail to gather at an outdoor rally in the Swedish capital, the mother of a British soldier killed in Iraq took the stage, putting the blame on the US and British leaders.

"George Bush and Tony Blair are liars. They sent my son to war. I am not going to see him again and it's wrong."