GENEVA - The United Nations committee against torture has demanded that the United States provide more information about its treatment of prisoners at home and foreign terrorism suspects held in Iraq , Afghanistan and Guantanamo Bay.

In questions submitted to Washington, the panel also sought information about secret detention facilities and specifically whether the United States assumed responsibility for alleged acts of torture in them, U.N. officials said on Tuesday.

"It is the longest list of issues I have ever seen," Mercedes Morales, a U.N. human rights officer who serves as secretary to the U.N. Committee against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, told reporters.

Washington is expected to send a delegation of 30 officials to defend its record at a meeting next month in Geneva of the committee, composed of 10 independent human rights experts.

The debate, set for May 5 and May 8, will focus on a report filed a year ago by the United States on its compliance with the Convention against Torture, which bans all forms of torture.

Washington said at the time it was abiding by the treaty and that any abuses of detainees in the Afghanistan and Iraq wars were not systemic. Critics called the report a whitewash.

The U.N. committee has responded, asking firstly how memoranda from the U.S. Justice Department declaring that torture covers only extreme acts is compatible with the treaty.

It asked whether there had been any independent investigation into "the possible responsibility of high-ranking officials" for authorizing or consenting to acts of torture committed during interrogation of detainees.

It seeks details on how many people are detained in Iraq, Afghanistan and the U.S. detention facility at Guantanamo Bay, Cuba, as well as their exact legal status.

On the Abu Ghraib facility in Iraq -- where photographs of torture and sexual abuse of detainees by U.S. soldiers provoked outrage in 2004 -- the U.N. committee asked what measures had been taken to "identify and remedy problems" there.

The U.N. panel cited reports of secret detention facilities, including on ships, and demanded a list of all detention facilities where inmates are held under de facto U.S. control.

"Why have such secret detention facilities been established? Does the (United States) assume responsibility for alleged acts of torture perpetrated by its own public agents outside its territory but in territories under its jurisdiction or de facto control...?" the U.N. committee asked.

It also challenged some practices in U.S. domestic jails, such as imprisoning juveniles with adults, banned under U.S. law. It cited a report that "detained women are kept shackled during childbirth," while other detainees are chained in gangs.

"There is serious concern on the part of the committee at the situation of (U.S.) prisons, the system and the conditions of detention which can be tremendously severe," Morales said.

The U.N. panel, which meets twice a year, will also examine the records of Georgia, Guatemala, Peru, Qatar, South Korea and Togo at its May 1-19 session.

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