The Guardian daily said it had seen flight logs documenting the flights by 26 planes operated by the Central Intelligence Agency (CIA).

The information showed an "unprecedented" amount of travel by the agency but did not reveal which planes took part in alleged prison transfers, it said.

The CIA has been accused in reports of using European countries for the transport, illegal detention and torture of suspected Islamist terrorists in the wake of the September 11, 2001 attacks on the United States.

The United States on Wednes-day promised a timely and forthright reply to an EU letter demanding answers to the claims.

The Guardian said the flight logs revealed that the CIA visited Germany 96 times and Britain 80 times, though when charter flights were added this figure rose to more than 200.

France was only visited twice and Austria not at all, the newspaper said.

The logs also showed regular trips to eastern Europe, including 15 stops in Prague.

"Only one visit is recorded to the Szymany airbase in north-east Poland, which has been identified as the alleged site of a secret CIA jail," The Guardian reported.

Poland and Romania have denied hosting CIA prisons, it added.

The Guardian said the flight logs were obtained from Federal Aviation Administration data and sources in the aviation industry.

In New York a leading human rights monitor published Wednesday the names of 26 "ghost detainees" that it accused the United States of holding and possibly torturing in secret overseas locations.

The prisoners, suspected of involvement in such acts as the September 11, 2001, attacks, the 1998 US embassy bombings in Kenya and Tanzania, and the 2002 nightclub bombings in Bali, Indonesia, are being held indefinitely and incommunicado, with no access to counsel, Human Rights Watch alleged.

According to the New York-based monitor, US government officials, speaking anonymously to journalists, have suggested that some of the detainees have been tortured or otherwise seriously mistreated in CIA custody.