Sunnis have also accused the ministry of being behind "death squads," rumored to be made up of former members of Shiite militias, which target Sunnis in reprisal for the killings of Shiites by Sunni Arab insurgents. Interior Minister Bayn Jabr has denied any role in such killings.
Kamal, the deputy interior minister, was quoted by CNN as saying the skin of some of the detainees in the Baghdad center had peeled off parts of their bodies. He later declined to confirm the allegation to The Associated Press.
Sunni Arab complaints have taken on new urgency because of American efforts to encourage a big Sunni turnout in the Dec. 15 parliamentary elections in hopes of undermining Sunni support for the insurgency. In recent days, Secretary of State Condoleezza Rice, British Foreign Secretary Jack Straw and U.N. Secretary-General Kofi Annan have all visited Iraq to promote Sunni participation.
U.S. officials have also been pressing the majority Shiites and their Kurdish allies to reach out to the minority community _ which dominated the country during Saddam's regime.
U.S. Ambassador Zalmay Khalilzad and the top U.S. commander in Iraq, Gen. George Casey, have expressed their "deep concern" over the condition of the detainees "at the highest level" of the Iraqi government, a U.S. Embassy statement said.
"We agree with Iraq's leaders that the mistreatment of detainees is a serious matter and totally unacceptable," the statement added.
But the case also raises troubling questions about the training and discipline of Iraqi security forces, which Washington hopes can assume a greater role in fighting the insurgents so that U.S. and other international troops can begin to go home.
Interior Ministry commandos, who are separate from the Iraqi army, spearhead the Iraqi government's campaign against the insurgency. Those commandos arrested more than 300 suspects last week in Diyala province after attacks on police checkpoints and a truck bomb that killed about 20 people in a Shiite village.
Many Sunnis fear that methods used by the Interior Ministry forces _ known by fearsome names such as the Scorpions and the Wolf Brigade _ are setting the stage for sectarian war.
"In order to search for one terrorist, they detain hundreds of innocent people and torture them brutally," Sunni politician Abdul-Hamid said.
Kamal, the deputy interior minister, said all detainees found at the center had been arrested under legal warrants issued by judges.
"They were mistreated and you know what happens in prison," Kamal told The Associated Press. "We will try to make sure that such acts are not repeated in the future."
He said the detainees were held in the basement of the building because the Justice Ministry lacked proper facilities and "there are no other places to hold those terrorists."
Saleh al-Mutlaq, a Sunni politician, insisted that torture is widespread in Interior Ministry detention centers and that the force has been infiltrated by the Badr Brigade, the military wing of Iraq's largest Shiite party.
"Some Iraqis are having their heads opened with drills, then their bodies are thrown in the streets," al-Mutlaq said. "This shows that the United States should stop these acts since it is the force that occupies Iraq."
Amnesty International welcomed al-Jaafari's decision to order an investigation but urged him to expand the probe to include all allegations of torture. Amnesty also asked him to make the results public. In Geneva, the International Committee of the Red Cross said it was unaware of the detention center but wanted to learn more.
In a report Monday, the U.N. mission in Iraq warned about detention conditions in Iraq. The report said 23,394 people were in detention in Iraq, including 11,559 held by multinational forces.
"There is an urgent need to provide remedy to lengthy internment for reasons of security without adequate judicial oversight," the report said.
