At least 40 people were killed and 127 injured in a series of car bombings in Iraq, the CNN reports.

Quoting an Iraqi Ministry of Health CNN said most of the deaths occurred in attacks in western Baghdad.

The blasts began early morning when two car bombs detonated at the opening ceremony led by Iraqi officials for a water pumping station in western Baghdad.

Immediately, just about half a mile away, another car bomb exploded at a checkpoint, 3km from the Baghdad University.

A suicide car bomber hit a compound used by US military and Iraqi police in Baghdad's Abu Ghraib neighbourhood, killing a soldier and several Iraqi police officials.

"This despicable act killed not only a Multi-National Force Soldier, but Iraqis who were merely going about their business of defending this country," CNN quoted Lt Col. James Hutton, a 1st Cavalry Division spokesman, saying.