Hundreds of Iraqis are being tortured to death or summarily executed every month in Baghdad alone by death squads working from the Ministry of the Interior, says the United Nations' outgoing human rights chief in Iraq.
John Pace, who left Baghdad two weeks ago, said up to three-quarters of the corpses stacked in the city's mortuary show evidence of gunshot wounds to the head or injuries caused by drill-bits or burning cigarettes.
Much of the killing, he said, was carried out by Shiite groups under the ministry's control.
Much of the statistical information provided to Pace and his team comes from the Baghdad Medico-Legal Institute, next to the city's mortuary.
He said that in last July alone the morgue received 1100 bodies, about 900 of which bore evidence of torture or summary execution.
The pattern prevailed throughout the year until December, when the number dropped to 780 bodies, about 400 of which had gunshot or torture wounds.
"It's being done by anyone who wishes to wipe out anybody else for various reasons," said Pace, who worked for the United Nations for more than 40 years in countries such as Liberia and Chile. "But the bulk are attributed to the agents of the Ministry of the Interior."
Coupled with the suicide bombings and attacks on Shiite holy places carried out by Sunnis, some of whom are followers of Abu Musab al-Zarqawi, al Qaeda's leader in Iraq, the activities of the death squads are pushing Iraq ever closer to a civil war.
Pace said the Interior Ministry was "acting as a rogue element" in the Government" and was controlled by main Shiite party, the Supreme Council for Islamic Revolution in Iraq (Sciri).
The Interior Minister, Bayan Jabr, is a former leader of Sciri's Badr Brigade militia, one of the main groups accused of sectarian killings.
Another is the Mehdi Army of the young cleric Moqtada al-Sadr, who is part of the Shiite coalition seeking to form a Government after winning the mid-December election.
Many of the 110,000 policemen and police commandos under the ministry's control are suspected of being former members of the Badr Brigade.
Not only counter-insurgency units such as the Wolf Brigade and the Scorpions, but the commandos and even the highway patrol police have been accused of acting as death squads.
The commandos, who dress in garish camouflage and hoods, are dreaded in Sunni neighbourhoods.
People they arrest frequently turn up dead several days later, their bodies bearing obvious marks of torture.
Pace, a Maltese-Australian who has now retired, said the constant violence and lack of security in Iraq were creating a vicious circle in which ordinary citizens were turning to extremist sectarian groups for protection.
But ordinary Sunnis are caught between the death squads and the desire of some insurgents on their own side to start a civil war - an aim they are now not far from achieving.
Last week's attack on the Golden Mosque is only the latest in a long series of outrages against the Shiites.
Despite continuing a 24-hour curfew yesterday in Baghdad, authorities were unable to prevent further revenge killings and holy site attacks.
An exchange of populations is taking place in Baghdad as members of each community move to districts where they are the majority.
Yesterday, Government ministers proposed putting tanks on the streets, while Sunni politicians resolved to help form a new Government.
In Pace's view, the violence in Iraq is being made worse by the seizing of Iraqis by US troops and Iraqi police.
"The vast majority are innocent," he said. "You don't eliminate terrorism by what they're doing now. Military intervention causes serious human rights and humanitarian problems to innocent civilians ... "
Pace, who first made his comments to The Times of Malta, said the situation in Iraq had "definitely, definitely" got worse over the two years in which he headed the UN human rights team.
The Government was trying to restart the country's crippled economy, but, he said, it would not succeed "until people are secure".
* Badr Brigade: Armed wing of the most powerful Shiite party. Many police and paramilitaries "still wear Badr T-shirts under their uniform", a US general said.
* Mehdi Army: Loyal to the Shiite cleric Moqtada al-Sadr. Its members in the police are accused of death squad killings.
* Defenders of Khadamiya: Followers of Hussein al-Sadr, Moqtada relative. Among forces set up to guard Shiite shrines, but having more sinister links.
* Special police commandos: Feared by Sunnis, despite having had some Sunni commanders.