Two US Marines have been killed in a car bomb explosion outside the Iraqi city of Fallujah. A military spokesman said a further six soldiers were wounded in what may have been a suicide bombing.
Earlier, US forces handed control in Fallujah to a former general in Saddam Hussein's Republican Guard.
Jasim Mohamed Saleh said his force of around 1,000 former soldiers would help police to bring order to the city where a month-long siege has cost hundreds of lives.
In another development, the US Vice President, Dick Cheney, has said the deadline of 30 June for ceding power to an interim Iraqi government would mark only the beginning of the transfer of sovereignty.
Speaking in Washington, he said insurgents in Iraq could step up violent attacks to derail plans to set an interim government in place ahead of elections, expected early next year.
Bush 'disgusted' by abuse
US President George W Bush has said he is disgusted by the abuse of Iraqi prisoners while in US military custody at the Abu Ghreib prison and that the US military would punish those responsible.
Pictures showing captives being mistreated at the prison have been published and broadcast around the world.
The pictures include images of naked and hooded prisoners being forced to sit on each other, and in some cases having wires attached to their bodies by laughing US soldiers.
Six soldiers, including a brigadier general, are facing court martial in Iraq, as well as a possible prison term over the allegations of abuse.
