Three other suspects, who survived the ordeal of being locked up in a van in the sun, were taken to hospital on Monday morning where they were to be interviewed by officials who are investigating the case, an Interior Ministry official said.
The incident began on Sunday in the Amariyah district of western Baghdad when one of 12 bricklayers sustained gunshots during a firefight between armed fighters and police.
His colleagues took him to a hospital in the Shuala district where he was pronounced dead.
Iraqi police commandos then arrived at the hospital where they arrested the 11, along with one other man who was there accompanying his pregnant wife.
The suspects were taken to the commando headquarters in the Jihad neighbourhood in western Baghdad where they were said to have been beaten and locked in the police van from 11am on Sunday to 1am on Monday.
There have been numerous allegations of brutality, particularly by police and commandos, against detained armed suspects.
Iraqi soldiers killed
Also on Monday, armed fighters stormed an Iraqi army checkpoint north of Baghdad, killing seven soldiers, while two more were killed in a car bombing an hour later.
Seven Iraqi soldiers died in
Monday's first attack
The first attack occurred at about 5am (0100 GMT) when armed men firing mortars and machine guns stormed a checkpoint in Khalis, about 70km northeast of Baghdad, Colonel Abdullah al-Shimmari said.
Seven soldiers were killed while three people, including one civilian, were injured in that attack.
At 6.30am (0230 GMT), a bomb in a parked car exploded as an Iraqi army patrol passed by, killing two soldiers and wounding another, al-Shimmari said.
In Tal Afar, west of Mosul, five Iraqis were killed and 18 others injured in a bombing targeting al-Qalaa and Hasan Kawi neighbourhoods, Tal Afar hospital sources told Aljazeera on Monday.
Nine houses were destroyed in the bombing, the sources added.
Aljazeera also learned that US and Iraqi forces have been surrounding Buhruz city, south of Baquba, since Sunday, preventing people from entering or exiting.
Nine homes were destroyed in
the Tal Afar bombing
The forces have launched raids and search operations in the city, arresting more than 50 Iraqis, witnesses and police sources told Iraqi journalist Walid Khalid, who spoke to Aljazeera.
Using loudspeakers, the US and Iraqi forces gave residents 24 hours to hand over fighters, or the city would suffer a massive military bombardment, Khalid reported.
The siege came after an Iraqi soldier was killed and another injured when an explosive device targeting an Iraqi army patrol detonated in the city.
In Baghdad on Monday morning, a blast rocked the Green Zone police sources told Khalid. US forces have refused to comment, he added.
In other developments, the influential Association of Muslim Scholars (AMS), accused the Iraqi Interior Ministry police commandos of killing nine Iraqi civilians, the Iraqi journalist said.
The civilians were detained by Iraqi policemen two days ago when they went to visit a man at al-Yarmuk hospital in the Khadamiya district. The man had been suffering from injuries sustained in an attack by US forces.
Hospital sources confirmed that the nine bodies were currently being held.
The AMS accused the police commandos of killing the civilians because they were Sunni Arabs from the Abu Ghraib area.
The police, however, said the men had been involved in clashes in the area of al-Amariya, west of Baghdad, Khalid said.
The US military announced on Monday that two US marines had been killed while conducting security operations in Hiyt, 150km west of Baghdad.
Scores of security recruits were
killed and injured on Sunday
According to a statement, they died as a result of "indirect fire" on Sunday, a term usually employed to describe a mortar attack. The attacks come as the US, Britain and Australia consider reducing the number of soldiers stationed in the war-torn country.
But Australia said on Monday it had not discussed taking over military command in southern Iraq from Britain, after it was reported London wanted to free up British troops for redeployment to Afghanistan.
British paper The Sunday Times reported that Australia and Britain were already in talks for a handover, while the Mail on Sunday, another British paper, said the UK and the US were planning to halve troop levels in Iraq by mid-2006.
But Australian Prime Minister John Howard denied the report. "There haven't been any discussions between the Australian government or Australian defence officials about that and it was frankly news to me," Howard said in Sydney.
Australia has 1370 defence personnel in and around Iraq, including 450 troops protecting Japanese engineers and training the Iraqi army.
US citizen released
Meanwhile, the US military in Iraq has freed an Iranian-born American filmmaker held as a suspected fighter after his family criticised his treatment during eight weeks of captivity.
Cyrus Kar, 44, was detained by Iraqi troops with his cameraman in Baghdad after a search of the taxi he was being driven in found washing machine timers, a common component in improvised bombs.
Kar's cameraman, Farshid Faraji, was also released.
A US Navy veteran, Kar had gone to Iraq in mid-May to work on a documentary about Cyrus the Great, a king of ancient Persia, his family said.
"He felt like he was a mushroom. He was left in the dark and fed garbage," Kar's cousin, Shahrzad Folger, said in Los Angeles after speaking to Kar following his release in Baghdad on Sunday.
Mark Rosenbaum, a lawyer with the American Civil Liberties Union, which filed a writ of habeas corpus on Kar's behalf, called on the US government to apologise to the Los Angeles resident.
Kar's passport, laptop computer, film equipment, 20 hours worth of footage from Iran and Iraq and personal effects were taken and destroyed, Rosenbaum said.
US officials defended the detention and said Kar was freed after an FBI investigation determined he was not an enemy combatant.
"Kar was detained as an imperative security threat to Iraq under the authority of the United Nations Security Council Resolution 1546," the US military said.
Kar was one of five Americans the Pentagon said it was holding last week. More than 10,000 Iraqis are also being detained.