A bomb exploded Friday under an oil pipeline south of Baghdad, spilling crude oil and sparking a huge fire, Iraqi police said. The explosives were planted under a pipeline in the al-Mowehlah area of Haswa, a town 50 kilometers (30 miles) south of the Iraqi capital, a police officer was quoted as saying by the Associated Press. The pipeline transmit crude oil from Iraq's southern oil fields to the Dora refinery in Baghdad. The blast ignited a huge fire around 5 a.m., the officer said. By midday, firefighters were still struggling to extinguish the flames, which were fueled by a continuing leak of oil from the pipeline, he said. Workers were also looking for a way to temporarily cut off the oil flow, until a repair could be made, the officer added.