Brussels, Belgium ? The European Union and the continent’s top human rights group said Thursday they will investigate allegations the CIA set up secret jails in eastern Europe and elsewhere to interrogate terror suspects, and the Red Cross demanded access to any prisoners.

Human Rights Watch said it has evidence, based on flight logs, that indicate the CIA transported suspects captured in Afghanistan to Poland and Romania. But the two countries – and others in the former Soviet bloc – denied the allegations. U.S. officials have refused to confirm or deny the claims.

Such prisons, European officials say, would violate the continent’s human rights principles. At work may be a complex web of global politics, in which eastern European countries face choices between the views of the European Union and their interest in close ties with the United States.

The International Committee of the Red Cross expressed strong interest in the claims, first reported Wednesday in the Washington Post, that the CIA has been hiding and interrogating some of its most important al-Qaida captives at Soviet-era compounds.

Red Cross chief spokeswoman Antonella Notari said the agency asked Washington about the allegations and requested access to the prisons if they exist.