A wave of anti-war protests began to roll across Europe and the Middle East on Thursday after the opening salvos of the war against Iraq sparked angry demonstrations in Asia and Australia.

Barely three hours after the first United States missiles struck Baghdad, a crowd that organisers put at 40,000 and which police said numbered "tens of thousands" brought Australia's second largest city, Melbourne, to a standstill.

In Germany, 50,000 school students marched from Berlin's central Alexanderplatz past the guarded US embassy and through the Brandenburg Gate.

The crowd whistled and chanted and carried banners saying "Stop the Bush fire", "George W Hitler", "No blood for oil".

"The war is illegal and it should be resolved by the United Nations," said 18-year-old David Stassek, carrying a banner that read: "Stop US imperialism". Pia Telschow, a 14-year-old from Berlin, said: "Bush is just carrying on his father's war."

Bigger demonstrations were planned for later on Thursday in the capital and in dozens of other towns and cities. Some 5000 pupils were also demonstrating in Cologne.

In France, the most vocal Western opponent of the war, a string of organisations planned a 1700 GMT (0500 NZT) rally outside the US embassy in Paris. The mission was barricaded off to the public by mid-morning and surrounded with 15-20 police vans, a water cannon and scores of police, some with riot shields.

By midday a small group of pro-Iraqi protesters had gathered at the adjacent Place de la Concorde and were joined by some 70 students from an Iraqi secondary school who shouted "Bush-Blair Assassins!" and other chants in Arabic.

In Italy, anti-war activists and labour unions staged demonstrations and downed tools. Protesters in Milan held a vigil in front of the city's cathedral while in Venice and Rome groups of hundreds gathered for spontaneous sit-ins.

"We want to bring cities to a standstill," said Luca Casarini, one of the organisers. "We don't want people to get used to the idea of war, to think it's normal."

Thousands more were expected to take part in a march to the US embassy in Rome in the afternoon. Public sector workers declared a day-long strike while Italy's three biggest unions, with a combined 11 million members, said they would strike for two hours to protest against the attacks.

In Greece, where there is bitter public and government opposition to the attack on Iraq, the centre of Athens was turned into a huge protest arena. Nearly 10,000 people including many schoolchildren gathered to march to the US embassy. Greek police rushed reinforcements to the embassy to protect it.

British anti-war campaigners blocked roads, boycotted schools and workplaces, and began gathering in public places.

"I am surprised how quickly the protests have kicked off," John Rees, of the umbrella Stop the War Coalition, said as he dashed to a gathering in London's Parliament Square.

In Spain, several hundred chanting demonstrators gathered outside the US embassy in Madrid.

Austria's capital Vienna saw a protest march by thousands of schoolchildren. Some 20 towns in Switzerland were preparing for demonstrations, with students and school pupils boycotting studies.

In the Gaza Strip, Palestinian children marched in the Rafah refugee camp, holding Iraqi flags and posters of Iraqi President Saddam Hussein, and setting fire to Israeli and US flags.

About 150 people marched in the West Bank city of Bethlehem waving Iraqi and Palestinian flags and carrying portraits of Saddam.

Egyptian police in Cairo's central Tahrir Square beat back protesters trying to reach the nearby US embassy and cordoned off the area, restoring order, security sources said.

Australia, a staunch ally of the United States, deployed armed police for the first time around parliament in Canberra and increased their presence at US diplomatic missions.

Anti-American sentiment was stronger still in Muslim Indonesia, Malaysia and Pakistan, where many saw the attack as the beginning of an American campaign to subjugate the Islamic world and seize control of oil.

In Pakistan there were scattered but peaceful rallies across the country against what some called "American terrorism".

Hundreds of people took to the streets of the commercial hub of Karachi, the cities of Multan and Lahore, and Peshawar on the northwest frontier with Afghanistan, as well as Rawalpindi.

Indonesia's biggest rally was in Jakarta, where 2000 people from a conservative Muslim party sang and chanted anti-American slogans outside the heavily-fortified US embassy. There were also protests in the cities of Bandung, Yogyakarta and Makassar. Local radio said police in the central Java city of Semarang had clashed with 50 students after they burned an effigy of US President George W Bush. Several students were slightly hurt.

- REUTERS