An oil pipeline south of
The blast, near the town of
The pipeline carries fuel south from
It was the second time in the past year the pipeline had been hit and the latest in a series of attacks on Iraqi oil refineries, blamed on fighters.
Pumping from the refinery was stopped because of the explosion, and production was likely to be affected, according to an official speaking anonymously.
A police officer, also speaking on condition of anonymity, said "the bombing has caused a huge fire".
He added that at least 16 firefighting units had been sent to the area to deal with the explosion.
But oil pipelines have often been targeted around the country by fighters or saboteurs.
PHOTO CAPTION
An oil pipeline south of