The apology was issued by Mr Bush's spokesman after the president appeared on TV in Iraq to condemn the abuse.

Photographs have shown Iraqi prisoners being tied up and made to look stupid. Mr Bush said the abuse did not represent "the America I know".

But many Iraqis were upset because he stopped short of saying sorry. Soon after, Mr Bush's apology was issued.

Meanwhile, new photographs apparently showing more abuse of Iraqi prisoners have been published in US newspaper The Washington Post.

Dog

One of them appears to show a prisoner being pulled along on a lead, like a dog.