In response to allegations of prisoner abuse at the U.S. Navy base in Cuba, Bush made the challenge in June, and again Wednesday while in Denmark.

However, a CNN crew that toured the facility was not allowed to see the worst-behaved inmates, who are kept in a block behind a mesh fence.

The prison holds about 520 prisoners from 44 countries, most of them captured during the U.S.-led war in Afghanistan.

CNN employees were not allowed to speak to the prisoners, and military censors demanded the crew erase video footage they said would allow viewers to identify a prisoner.

In the hospital wing, one prisoner shouted in English, "We take the torture in here," but it was not possible to talk to the prisoner about his allegation, the network said.