Nine bombings mainly targeting Shiite-majority areas of Baghdad killed at least 14 people and wounded dozens more on Wednesday, officials said, as Iraq suffers its worst violence in years.

The country has been hit by a year-long surge in bloodshed that has reached levels not seen since 2008, driven by widespread discontent among its Sunni Arab minority, and by the bloody civil war in neighbouring Syria.

Baghdad is one of the most frequently-targeted cities in the country and is hit by near-daily bombings and shootings.

The seven car bombs and two roadside bombs, which struck in six different areas of Baghdad, also wounded more than 70 people, the sources said.

The deadliest single attacks were car bombs in the Karrada district of central Baghdad and Shuala in the capital's north, each of which killed three people.

While there was no immediate claim of responsibility for the attacks, Sunni jihadists often target members of Iraq's Shiite Muslim majority, whom they consider apostates.

The Baghdad blasts came a day after suicide bombers attacked the city council headquarters in Samarra, north of Baghdad, and took employees hostage.

Another bomber detonated an explosives-rigged vehicle after police and anti-Al-Qaeda militiamen arrived at the scene, while the two inside the building also blew themselves up after exchanging fire with security forces.

The violence, which showcased the impunity with which militants can strike even targets that should be highly secure, killed five people and wounded 47.

Militants have carried out similar assaults elsewhere in Salaheddin province, north of Baghdad, and battled security forces for control of the Sulaiman Bek area, leaving dozens dead.

The Iraqi government also faces a more than two-month crisis in Anbar province, west of Baghdad, where it has lost all of the city of Fallujah as well as shifting parts of provincial capital Ramadi to anti-government fighters.

It is the first time anti-government forces have exercised such open control in major cities since the peak of the deadly violence that followed the US-led invasion of 2003.

More than 370,000 people may have been displaced by violence in Anbar during the latest crisis, according to the United Nations.

Violence in Iraq has killed more than 1,790 people since January 1, according to AFP figures based on security and medical sources.