Prosecutors have previously said that the term "special strikes" in Iraqi documents refers to the use of chemical weapons such as mustard gas or sarin.

The document, signed by Nazar Abdul Kareem Faisal, the Iraqi chief of staff, read: "There must be full destruction of saboteurs in the northern area."

The documents also showed that the Iraqi forces were told to co-operate with their Turkish counterparts during a 1980s campaign against Kurdish civilians, according to evidence presented to a court trying Saddam.

In a revelation likely to stir anger among Kurdish survivors, the memo orders the Iraqi officers "to co-operate with the Turkish side, according to the co-operation protocol with them to chase all the refugees".

No detail was given of the alleged agreement between Turkey and Iraq, and a Turkish official denied that Ankara had any role in the campaign.

While Ankara has long opposed the idea of an independent Kurdish homeland in northern Iraq, it has never been proved that Turkey co-operated with Saddam's forces during Anfal, which prosecutors describe as genocide.

While the document touching on Turkish links was read out, sound was cut off to trial reporters and no discussion of the memo could be heard, although the Arabic-language document could still be read on the court screens.

Saddam and six co-defendants are accused of killing 182,000 Kurds between 1987 and 1988, when government troops allegedly suppressed a Kurdish uprising by using artillery, air strikes, death camps and poison gas attacks.

They insist that the so-called Anfal campaign was a legitimate counter-insurgency operation against Kurdish separatists at a time when Iraq was at war with Iran.

Saddam was sentenced to death a month ago for his role in the execution of 148 Shias in revenge for an assassination attempt against him in the town of Dujail in 1982. A panel of appeal court judges is reviewing the verdict.

The Anfal trial was adjourned until January 8.