ANKARA, Turkey (AP) _ An explosion damaged part of the oil pipeline linking Iraq to Turkey on Sunday, cutting the oil flow, a pipeline official said.

The cause of the blast was unknown, said the official, speaking on customary condition of anonymity from the site of the explosion in Midyat in the southeastern province of Mardin.

Workers extinguished a fire caused by the blast. It was not clear when the flow of oil could resume through the pipeline, though Mardin Gov. Fikret Guven described the damage as light.

About half the oil Iraq exports flows through the pipeline, some 1 million barrels a day.

Guven said authorities were not ruling out the possibility of sabotage.

Oil transport between Iraq and Turkey resumed earlier this month after U.S. warplanes attacked the Iraqi communications centers that controlled the flow of the pipeline's oil.

Iraq has been barred from exporting oil freely since U.N. sanctions were imposed in 1990 to punish Iraq for invading Kuwait. Under a U.N. oil-for-food program, Iraq can sell $5.2 billion worth of oil over six months to buy food, medicine and other humanitarian goods.