Firefighters say they have extinguished a massive fire that raged for hours after an oil pipeline exploded in Iran\'s Khuzestan province. The fire broke out early Friday in a pipeline transporting crude oil to the provincial capital of Ahvaz, 543 miles southwest of Tehran, PressTV reported. The pipeline, one of the longest in Iran, can transport almost 4,000 barrels of oil per day. Hundreds of firefighters and engine units battled the blaze that spread along almost 1,000 feet of the pipeline with flames as high as 100 feet. It took 10 hours to extinguish the fire, authorities said. Iran is the world\'s fourth largest oil producer.