Car bombs in Iraq killed six people on Wednesday as authorities released figures showing nearly 70,000 people died in violence from 2004 to 2011, markedly fewer than numbers from other sources.

The latest bloodshed comes a month before Baghdad hosts an Arab summit, the first such non-emergency Arab meeting to be held in the Iraqi capital in more than 30 years, and less than a week after a wave of attacks claimed by Al-Qaeda killed 42 people nationwide.

In Baghdad, a car bomb in the eastern Ameen neighbourhood killed three people and wounded at least nine, security and medical officials said.

Another car bomb in the town of Tuz Khurmatu, 175 kilometres (110 miles) north of Baghdad, struck as a joint army-police patrol was passing.

Three security force members -- an army lieutenant colonel, a policeman and a soldier -- were killed, and one soldier was wounded, according to Lieutenant Colonel Jassim al-Bayati of Tuz police and Dr Hidayet Mustafa at Tuz hospital.

In Diyala province north of the capital, gunmen attacked a checkpoint east of the provincial capital Baquba late on Tuesday, killing a member of the Sahwa anti-Qaeda militia and wounding two others, a police lieutenant colonel said.

The Sahwa are made up of Sunni Arab tribesmen and former insurgents who joined forces with the US military against Al-Qaeda from late 2006, helping to turn the tide against the insurgency.

Violence in Iraq is down from its peak in 2006 and 2007, but attacks remain common, killing 151 people in January.

The government, meanwhile, said in a statement that 69,263 people were killed as a result of violence in Iraq from 2004 to 2011, significantly fewer than figures from other sources, including one of its own ministries.

"Iraqi government spokesman Ali al-Dabbagh announced that the number of victims ... from April 5, 2004 to December 31, 2011 reached 69,263 martyrs and 239,133 wounded," the statement said.

"These figures represent the total number of victims who fell as a result of terrorist attacks and violence and military operations," the statement said.

The figures come from the health ministry and national security council, it added.

The deadliest year was 2006, when 21,539 people were killed and 39,329 wounded, as Iraq was engulfed in bloody sectarian conflict, while in 2011, 2,777 people were killed, the statement said.

Baghdad province saw the highest number of people killed between 2004 and 2011 at 23,898, while Muthanna province in the south saw the lowest at 94, it said.

However, the numbers are significantly lower than previous figures that cover a shorter time span, including figures from Iraq's own human rights ministry.

The human rights ministry said in an October 2009 report that 85,694 people were killed from 2004 to 2008.

And the US military's Central Command posted figures on its website in July 2010 that indicated that 76,939 Iraqis, including security forces members, had been killed from January 2004 to August 2008.

Independent British website www.iraqbodycount.org says that at least 114,584 civilians were killed in violence in Iraq from the US-led invasion of 2003 through December 30, 2011.