A U.S. soldier guarding his position in a watch tower at the Abu Gharib prison (AFP)

BAGHDAD, April 20 (IslamOnline.net & News Agencies) - Twenty-two people were killed and some 92 others injured in a mortar attack Tuesday, April 20, on the U.S.-run Abu Gharib prison, west of Baghdad.

At least 18 mortar rounds rained down late in the afternoon on the prison, Agence France-Presse (AFP) quoted as saying Brigadier General Mark Kimmitt, the U.S.-led occupation's deputy director of military operations.

Twenty-five of the badly injured people were taken away by helicopter, some to the fortified green zone in the centre of Baghdad for treatment.

Kimmitt said he did not know whether the victims were suspected criminals or "security detainees" from U.S.-led operations in the country.

An occupation spokesman, however, said later that 4,400 "security detainees" were held at the jail, one of the largest U.S.-run prison facilities in Iraq, which has regularly come under attacks.

The International Committee of the Red Cross (ICRC) said according to figures it has been given by the occupation authority, the facility holds some 6,500 inmates, of which about 2,000 are inside for criminal offences.

The Iraqi Red Crescent was called in to help because of the scale of the wounded at the prison. Few further details were immediately available.

In February, 33 mortar shells and five rockets were fired by unknown people at the prison before U.S. troops shot one person dead and arrested 55.

Barely a week earlier, another Iraqi civilian was hurt in an attack.

Last August, three mortar rounds were fired into the complex, killing six Iraqi detainees and injuring many more.

According to occupation estimates released last month, some 8,000 Iraqis were being held in the jail because they are considered to be a threat to security.

The notorious facility has remained a top-security institution since the Americans invaded the oil-rich country, denying journalists access to the site.

Human rights groups have complained that many detainees have been held in squalid conditions and that some of them had been mistreated.

In March, six U.S. military police officers had been charged with maltreatment, assault and indecent acts against prisoners at the prison.

The London-based human rights watchdog Amnesty International submitted a 25-page report to the U.S.-led occupation administration in Iraq on "excessive use of force, shooting demonstrators, maltreating prisoners and civilians by American soldiers."

On Sunday, August 17, U.S. troops shot dead Mazen Dana, an award-winning Reuters cameraman, while he was filming outside Abu Gharib prison.