George Bush said on Friday Saddam Hussein's fall had removed a source of Middle East violence and instability, and called on other countries to show more resolve against terrorism. Bush urged other countries to stay the course in Iraq after Spain vowed to pull out troops and South Korea refused to take on a combat role. "Any sign of weakness or retreat simply validates terrorist violence and invites more violence for all nations," Bush told representatives from 83 countries at the White House. Meanwhile, anti-war activists were taking to the streets in cities around the world to mark the first anniversary of the US-led invasion of Iraq, but organizers were not counting on the massive turnout seen at pre-war rallies. The biggest crowds in Europe were expected in Britain, Spain and Italy, whose governments backed US President George W. Bush's call to war to oust Saddam Hussein despite massive public opposition. In London, two anti-war demonstrators climbed to the top of London's landmark Big Ben clock tower early Saturday, as opponents of the the US-anglo invasion of Iraq prepared to kick off a march from Hyde Park to Trafalgar Square at noon (1200 GMT) to demand an end to the occupation of the oil-country. The Stop the War Coalition, which helped bring more than one million people into the streets on London in February 2003 to denounce the Iraq war, said tens of thousands of people were expected to join Saturday's march. In Spain, thousands of people, with the horrors of last week's Madrid train bombings fresh in their minds, were expected to join anti-war marches. Protest rallies were also scheduled in Italy, where a majority of people favour pulling out Italian troops from Iraq at the end of June, as well as in France, Germany and the United States. In France, an early opponent of the Iraq war along with Gremany, anti-war rallies were planned in several cities, including Paris, Marseille, Lyon and Toulouse. In the United States, protest organisers said they hoped their ranks might be swelled in the aftermath of the Madrid train bombings. In Australia, thousands of anti-war activists also staged rallies to mark the first anniversary of the US-led war. Speakers at the rallies called for Australian troops to be sent home from Iraq and attacked Prime Minister John Howard's conservative government's strong ties with the United States. About 2,000 people marched in Sydney, bearing an effigy of Howard with a large Pinocchio nose above a banner labelling him a war criminal. In Tokyo, organisers claimed 30,000 people had turned out to call for peace in Iraq and the immediate withdrawal of US and Japanese troops. Hundreds of people also rallied in Muslim-majority Indian Kashmir and in Bangladesh to demand foreign troops withdraw from Iraq. In Dhaka, activists staged rallies in which they shouted out slogans against the "repression" of Iraq and demanded the Bangladeshi government not hold talks with US Ambassador Harry Thomas. In the Philippines, riot police Saturday used water cannons to disperse a group of demonstrators who tried to march on the US embassy in Manila to protest the Iraq war. The Philippines has deployed 96 soldiers, police and aid workers to help coalition forces in Iraq and has rejected calls to withdraw them despite fears that this may expose the country to terror attacks. **PHOTO CAPTION*** A Greenpeace protestor sits on the face of London's landmark Big Ben clock tower. (AFP/Odd Andersen)