One of the biggest crowds joined the rally in San Francisco

Rallies took place in a dozen cities, with the biggest crowds gathering in New York, Chicago and San Francisco.

They were timed to coincide with the fifth anniversary of a vote by the US Senate to authorise the Iraq invasion.

Those taking part, who included relatives of servicemen fighting in Iraq, urged the US congress to cut off funding for the war.

The 'national day of action' was called by the United for Peace and Justice coalition.

Silence for dead

Mike Carano, who organised a march in Ohio, told Reuters news agency: "This is across-the-country sentiment about ending the occupation, redirecting funds for needs in this country, our attempt to get Congress to stand up and have its prerogative to cut funding, to take charge."

One of the national co-ordinators of the protests, Leslie Kielsen, told Reuters that the "half a trillion" dollars spent on the war was money that could have been used for education, social housing and to feed the hungry.

In New York participants gathered in Union Square, before marching on to Foley Square, which is close to many of the city's largest courthouses and government offices.

A two minute silence was held to honour those killed in the violence which has blighted Iraq since the 2003 US-led invasion.

An estimated 10,000 people joined a march in Chicago and in San Francisco there was an even greater turnout.