The pictures of Iraqi prisoners being abused by U.S. soldiers have shocked the world. But human rights groups say they have been raising the allegations of prisoner abuse in Iraq for some time.

Allegations that prisoners have been abused in U.S. military custody have been circulating for at least a year, but they stirred little attention - until now.

Alastair Hodgett, a spokesman for Amnesty International, says human rights groups have been investigating numerous allegations of prisoner abuse in Iraq since the early days of the U.S.-led occupation last year, and even longer in Afghanistan.

"Sadly they're anything but new," he said. "Amnesty International and other human rights groups have been raising concerns about ill-treatment, specifically at Abu Ghraib prison in Baghdad, since July of last year."

He said that Coalition Authority officials assured Amnesty International researchers that the allegations were being investigated.

Marc Galasco, military analyst at Human Rights Watch, says that in the wake of the revelations about Abu Ghraib prison, human rights organizations are receiving and investigating more claims of abuse of prisoners in U.S. military detention facilities.

"We are hearing a lot more," said Marc Galasco. "Now that's troubling on two sides. One, it's troubling because the potential exists that there have been a lot more types of abuse that have not been reported, and now people feel as if they're empowered and can come out and talk to us. But there's also the potential that you have those who come out with just stories because they're trying to get something. And so it's very important that we and others take the time to vet these sources of information and try to understand what actually happened."

Human rights groups have to generally rely on the accounts of prisoners who have been released, and those accounts are difficult to verify.

In an Arabic media interview, President Bush said Wednesday that while the first time he saw pictures of abuse at Abu Ghraib prison was when they were broadcast, an investigation of mistreatment of prisoners has been under way since the beginning of this year:

"The first time I saw - heard about pictures - was on TV," said President Bush. "However, as you might remember, in early January, General Kimmitt talked about an investigation that would be taking place about accused, you know, alleged improprieties in the prison. So our government has been in the process of investigating. And there are two, there are more than two investigators, multiple investigations going on, some of them related to any criminal charges that may be filed."

The president vowed that those responsible for the abuse of prisoners will be brought to justice.