The international Red Cross said Thursday that it had repeatedly asked U.S. authorities to take action over alleged prisoner abuse at Iraq's Abu Ghraib (search) prison before recent revelations about the way detainees were treated.

"We were aware of what was going on, and based on our findings we have repeatedly requested the U.S. authorities to take corrective action," said Nada Doumani, spokeswoman for the International Committee of the Red Cross (search), speaking from Amman, Jordan.

The ICRC, which visits prisoners held by coalition authorities in Iraq, had previously declined to comment publicly on conditions at the prison.

"We've been visiting Abu Ghraib prison since already from last year," Doumani told The Associated Press. "We are of course aware of the situation since we talk with the detainees privately.

"We get testimony from them. We visit all the premises in this place. We crosscheck information we receive from different detainees. Definitely we were aware of what was going on in Abu Ghraib.

Doumani said the visits have been taking place every five or six weeks since last year. The most recent visit was March 20, she said.

The scandal over treatment of prisoners began when CBS television broadcast pictures of smiling American guards with Iraqi prisoners in humiliating positions. That unleashed a huge international outcry.

The ICRC is designated by the Geneva Conventions (search) on warfare to visit prisoners of war and other people detained by an occupying power. It traditionally discusses its observations only with the detaining authority, but has been under pressure to say whether it had specifically warned the United States about prisoner abuse before the photographs came to light.

Doumani didn't say specifically when it gave its first warnings, but that it was over a period of months.