BAGHDAD, June 13: The US-led coalition plans to keep between 4,000 and 5,000 prisoners in its custody after the return of sovereignty to Iraq later this month, a US officer said on Sunday.

Another 1,400 detainees will be released or handed over to the new Iraqi authorities before the transition deadline of June 30, said Lieutenant Colonel Barry Johnson. "Currently, there are approximately 6,400 detainees," Johnson told reporters.

"At this time, we estimate there will be approximately 4,000 to 5,000 detainees after June 30, keeping in mind that anti-coalition activities occur every day, resulting in further detentions."

The International Committee of the Red Cross has warned the coalition that the Geneva conventions require it to release all detainees still in its custody at the end of its more than 14-month occupation, unless they have been charged.

"If the occupation is ended, the occupying forces have to release all the war prisoners, civil internees and security detainees except if there is a penal charge against them," ICRC spokeswoman Nada Doumani said.

A coalition spokesman said only 500 detainees' cases "have been deemed appropriate for prosecution". He said "45 cases are currently active and being processed for hearings and trials before the Central Criminal Court of Iraq."

Johnson said the coalition would shut down one of its three main prison centres in Iraq before the power handover. "Currently, there are three theatre-level detention facilities in Iraq - Camp Redemption at Abu Ghraib, Camp Bucca near Umm Qasr, and Camp Cropper (at Baghdad airport).

"The plan is to have only two theater-level facilities after June 30, Camp Redemption and Camp Bucca," he said. The majority of the 44 most-wanted members of Saddam Hussein's regime currently in coalition custody are held at Camp Cropper, a humanitarian group said.

For several months now, the coalition has been implementing an early release programme for low-threat detainees. The policy has been accelerated following the graphic revelations earlier this year of abuses of detainees by US warders at the notorious Abu Ghraib prison on the western outskirts of Baghdad.

In March, Abu Ghraib alone held more than 6,000 prisoners, but a succession of releases over the past month has sharply reduced its inmate population. Today only, 6,400 security detainees remain throughout the entire penal system and just 3,200 prisoners are held at Abu Ghraib, according to the US military.

The head of the US-run penal system, Major General Geoffrey Miller, told reporters in May the total number of detainees at Abu Ghraib would be cut to between 1,500 and 2,000 inmates by the summer. On May 21, Camp Bucca was holding 2,579 prisoners. -AFP