The US has been criticised over its interrogation techniques

It says torture and personal abuse - including sexual acts and attacks on religious beliefs - are intolerable.

CIA Director Michael Hayden said the order gave the agency the legal clarity it had been seeking.

The administration has faced pressure at home and abroad over interrogation techniques used on suspected militants.

What is needed now is repudiation of brutal and cruel interrogation methods

Leonard Rubenstein

Physicians for Human Rights

The most controversial practice allegedly used by the CIA is "water boarding" - in which prisoners are strapped to a plank over water and made to fear that they will drown.

The American authorities have never confirmed they use the technique and it is unclear whether the guidelines allow it.

Leonard Rubenstein, director of Physicians for Human Rights, told the Associated Press news agency that the executive order was inadequate.

"What is needed now is repudiation of brutal and cruel interrogation methods."

"General statements like this are inadequate, particularly after years of evidence that torture was authorised at the highest levels and utilised by US forces," he said.

Protection

The White House declined to say whether the CIA currently had a detention and interrogation programme.

But it said that if it did, the agency had to adhere to the guidelines.

Mr Hayden said the executive order gave CIA officers "the assurance that they may conduct their essential work in keeping with the laws of the United States".

Military lawyers say the main point of the orders is to offer protection to CIA officers who might get sued in US courts if they were deemed to have abused prisoners.

Mr Hayden will issue written policies to govern the programme and has asked the justice department to prepare a legal opinion on techniques the agency can use, according to a senior CIA official.

The order says that any interrogation practices used must be determined safe on an individual basis.

But the BBC's Duncan Kennedy in Washington says critics are likely to argue the new rules are still vague and give the administration far too much scope for using what they regard as unacceptable techniques.