The Bush administration's policy for detaining terror suspects came under sharp criticism after the revelation of a secret prison system ran by the CIA in foreign countries, US media reported Thursday.

United Nations officials said they will seek more information about the covert prisons, referred to as "black sites" in classified US documents.

"Every secret place of detention is usually a higher risk for ill treatment, that the danger of secrecy, " said Manfred Nowak, the UN's special rapporteur on torture, adding that he wants to pursue access to all US detention facilities outside its territory.

US congressional Democrats and human rights groups also warned that the secret system would damage the US image overseas.

House Democrats said they plan to introduce a motion later in the day to endorse language in the defense spending package written by Republican Senator John McCain, which will bar cruel and inhuman treatment of prisoners in US custody, including those in CIA hands.

McCain's amendment was endorsed last month by the Senate despite objection by the White House.

Congressman John P. Murtha, a ranking Democrat, urged the Bush administration to adopt a doctrine of "no torture, no excuses."

US Human rights groups said the prisoners held by the CIA should be brought to trial, rather than held indefinitely in covert prisons in which they have no recognized legal rights.

"What is really clear is that this is a dead-end policy and they are close to the dead end," said Tom Malinowski of Human Rights Watch.

According to a report of The Washington Post Wednesday, the covert prison system was set up by the US spy agency CIA nearly four years ago and has at various times included sites in Thailand, Afghanistan and several Eastern European countries as well as the US naval base in Guantanamo Bay, Cuba.

Source: Xinhua