The bipartisan Iraq Study Group released recommendations for changing course in the country, saying President Bush's policy in Iraq "is not working." The Iraqi government said the U.S. report did "not come as a surprise," and it agreed that Iraq must take the lead in its own security."

The situation is grave, very grave in fact, and cannot be tolerated," Deputy Prime Minister Barham Saleh said on the pan-Arab satellite TV channel Al-Arabiya. "Absolute dependence on foreign troops is not possible. The focus must be on boosting the Iraqi security forces."

The U.S. military said in a statement that 10 Americans had died in four separate incidents but gave no further details, pending notification of relatives. In addition to the 10 casualties, the U.S. command said two U.S. soldiers were killed Sunday in Baghdad and a Navy sailor were killed in Anbar province on Monday.

The latest deaths raised to at least 30 the number of U.S. troops who have died this month. At least 69 troops were killed in November and 105 soldiers were killed in October _ the highest amount for a month since January 2005.

At least 2,918 service members have been killed since the war started in 2003, according to an Associated Press count. In other violence Wednesday, two mortar rounds landed and exploded in a secondhand goods market in a mixed Shiite-Sunni area in central Baghdad, killing at least eight people and wounding dozens, said police officers Ali Mutab and Mohammed Khayoun, who provided the casualty totals.

About 25 minutes later, a suicide bomber on a bus in Sadr City detonated explosives hidden in his clothing, killing two people and wounding 15, police 1st Lt. Thaer Mahmoud said.

It appeared to be the first attack by suspected Sunni Arab insurgents on the large slum since Nov. 23, when a bombing and mortar attack killed 215 people in the deadliest single attack since the Iraq war began more than three years ago.

A total of at least 75 people were killed or found dead across Iraq on Wednesday, including 48 whose bullet-riddled bodies were found in different parts of the capital.

The latest eruptions of Iraq's unrelenting sectarian violence came hours before the release of a study by the Iraq Study Group, a blue-ribbon panel headed by former Secretary of State James A. Baker III and former Rep. Lee Hamilton, D-Ind.

 "The situation in Iraq is grave and deteriorating," the commission warned in the report.

It recommended the U.S. reduce political, military or economic support for Iraq if the government in Baghdad cannot make substantial progress toward providing for its own security.

On the highly emotional issue of troop withdrawals, the commission warned against either a precipitous pullback or an open-ended commitment to a large deployment.

Military priorities must change," the report said, toward a goal of training, equipping and advising Iraqi forces. "We should seek to complete the training and equipping mission by the end of the first quarter of 2008."

Saleh, the deputy prime minister, said the government agreed with the broad recommendations of the panel but acknowledged "there may be some details on which we differ." He did not elaborate.

The recommendations, at least principle, are in agreement with the national Iraqi vision that calls for reinforcing Iraqi capabilities, the handover of the security file to Iraqis and the respect of the Iraqi will," he told Al-Arabiya.

He also warned that improving the battlefield capabilities of the Iraqi armed forces would not be "the magic wand that brings a solution in one day."

Some Iraqis, while critical of U.S. strategy in Iraq, said they feared any new policy would lead to more suffering for their country.

They (U.S officials) are defeated in Iraq. So they are trying to seek for an outlet to get out of their plight in Iraq. And I think the outlet will be at the expense of the Iraqi people," Maan al-Obeidi, a professor and political analyst at al-Nahrain University in Baghdad, told AP Television News.

Elsewhere in Iraq, gunmen broke into a school in western Baghdad at noon, killing its Sunni headmaster in his office, then instructing teachers not to return, an Iraqi army officer said, speaking on condition of anonymity due to security concerns.

The attack came a day after Prime Minister Nouri al-Maliki urged university professors and students to ignore a Sunni Arab insurgent group's warnings to avoid class, calling them "desperate attempts."

The group had sent e-mails to students and posted signs at schools and mosques saying students should stay away while it cleanses the campuses of Shiite death squads, according to a statement from al-Maliki's office late Tuesday.

The government also announced the capture of a senior aide to Abu Hamza al-Muhajir, also known as Abu Ayyub al-Masri, who took over as leader of al-Qaida in Iraq after his predecessor Abu Musab al-Zarqawi was killed in a U.S. airstrike in June.

Mouwafak al-Rubaie, the government's national security adviser, said U.S. and Iraqi forces captured the aide, though he did not specify where or when. He said 60 percent of al-Qaida in Iraq's leadership has now been captured or killed.

Coalition forces have also detained several leaders of Ansar al-Sunnah, an insurgent group allied with al-Qaida in Iraq, al-Rubaie added.

The noose is tightening around Abu Ayyub al-Masri, and I can say with all confidence that al-Qaida in Iraq is undergoing a very real leadership crisis," al-Rubaie said at a news conference.

U.S. ground and air forces also conducted a raid targeting foreign insurgents near the Iranian border, killing a militant who opened fire on an aircraft, the U.S. command said.

The early morning raid took place near Khanaqin, a remote desert area 85 miles northeast of Baghdad where U.S. forces have helped Iraqi soldiers set up outposts designed to stop foreign insurgents and their weapons supplies from crossing into Iraq.

A coalition aircraft was leaving the raid when it took small arms fire from a vehicle below; it returned fire, destroying the vehicle and killing its armed insurgent, the command said. One suspected militant also was detained in the raid, which resulted in no U.S. casualties, the statement said.