Hundreds of thousands of people participated in anti-war protests, demonstrations, concerts and peace rallies around the world.
Where did the protests take place?
Marches and demonstrations were held outside the Pentagon in Washington DC and in major cities across the US including Los Angeles, San Francisco, San Diego, Hollywood, New York, North Carolina, and Connecticut.
Large peace demonstrations were also held outside US embassies and memorials in Spain, Turkey, Greece, Denmark and Hungary.
Smaller demonstrations were held in cities in Australia, South Korea, Malaysia and Japan.
The largest gathering was in Madrid, Spain where an estimated 400,000 protestors marched peacefully to the memorial for the 191 people killed in the train bombings on March 11, 2004.
When did the protests happen?
They started on Friday night and continued throughout the weekend ahead of the anniversary of the US-led invasion, which began on Tuesday March 20, 2003.
Why are they protesting?
The demonstrators are calling for foreign troops to be withdrawn from Iraq and were part of an organised international weekend of the 'Anti-war' movement.
It is the fourth anniversary of the US-led invasion of Iraq, where hundreds of thousands have been killed. They are against the Bush administration's policy and are demanding an end to the war.
Who is involved?
The people who protested are from many walks of life, including Vietnam war veterans, ex anti-Vietnam war protesters, grandparents, politicians, students, Muslims, Christians, anti-war activists, and the families people who have died in Iraq.
How did the protesters voice their opinions?
They carried banners displaying anti-war sentiment such as 'US Out of Iraq Now' and 'Stop the War in Iraq'. Some lit candles, chanted anti-war slogans, painted their faces and listened to anti-war activists and politicians speaking at worldwide events.