At least 27 others were wounded in the 7:30 am (0430 GMT) attack in the Bab al-Sharji neighbourhood. The nearby Neurological Hospital took in five dead and 13 wounded, while al-Kindi Hospital treated 14 injured, officials at the two hospitals said.

The attacker took advantage of interior ministry guards opening the compound's main gates to allow in electrical maintenance workers to ram his explosives-packed car through and set it off, a ministry official said, speaking on condition of anonymity.

The blast came after violence across Baghdad on Thursday killed 60 people.

Iraq is mired in political dispute with authorities calling for the arrest of Sunni Arab Vice President Tareq al-Hashemi on charges he ran a death squad, accusations Hashemi denies.

Prime Minister Nuri al-Maliki has also called for the sacking of his Sunni deputy Saleh al-Mutlak, who has denounced the premier as a dictator "worse than Saddam Hussein".

The Sunni-backed Iraqiya bloc, to which both Hashemi and Mutlak belong, has boycotted the cabinet and parliament.

Six Iraqi security members killed in attacks
Baghdad (AFP) Dec 25, 2011 - Gun and bomb attacks killed six members of Iraq's security forces -- four policemen and two soldiers -- in the Sunni provinces of Salaheddin and Anbar Sunday, security and medical officials said.

In the deadliest attack, three policemen were killed and six wounded in the village of Garma, east of the former insurgent bastion of Fallujah, when gunmen attacked their checkpoint, Anbar provincial police chief Major General Hadi al-Ruzaij said.

In Fallujah itself, gunmen shot dead a policeman who was on his way home in the centre of the town, 60 kilometres (40 miles) west of the capital, Fallujah hospital doctor Omar Dalli said.

Meanwhile, in the central town of Dujail, north of Baghdad, a suicide attacker rammed a car bomb into a checkpoint on a highway linking the capital to Tikrit, capital of Salaheddin province, an official in the provincial security command centre said.

The attack left two soldiers dead and four others wounded, said the official, who spoke on condition of anonymity. Eight civilians were also hurt.

Attacks are down from their peak in 2006 and 2007, but violence remains common in Iraq. A total of 187 people died in attacks in November, according to official figures.

"The country is facing significant security problems," he said, pointing to a string of attacks since last week that have claimed dozens of lives.

But Kobler does "not expect the outbreak of civil war" although he said there is a policy deadlock in the country, according to an interview published in the Berlin daily Tagesspiegel.

The UN envoy said he was neither optimistic nor pessimistic about the future of Iraq after the departure of US forces earlier this month but said: "I am realistic and take the facts into account."

"Iraq now has security forces and they are in a far better state than some years ago. There will be no break-up of Iraq."

Just days after the last US troops left on December 18, Iraq was shaken by a number of attacks, against the backdrop of a deepening political crisis between the Shia majority and the Sunni minority.

A suicide attack on Monday killed five people and left dozens wounded at the interior ministry in Baghdad.

Last Thursday a wave of attacks across the capital killed 60 people, and violence in the provinces the same day claimed another seven lives. It was the deadliest day in Iraq since mid-August.