US group warns of crisis of displaced Iraqis

California-based International Medical Corps (IMC), which has more than 300 staff in Iraq, said the pace of people displaced was rising at a "dramatic rate", particularly in the capital, which has a population of about 6 million.

"It is a very tough situation. There is a terrible security situation there with an increasing number of people who are displaced," said Nancy Aossey, president of the group.

A study by her group found 80 percent of the nearly 550,000 Iraqi civilians who had fled their homes since the Feb. 2006 bombing of a Shi'ite shrine in Samarra, were in Baghdad. The Samarra bombing triggered a wave of sectarian killing.