State-run media said the pipeline blew up Friday evening, and more than 2,000 firefighters worked overnight to control flames and further blasts on a second pipeline.
China Central Television showed the fire raging among tanks at the port in the northern city of Dalian, and state media described flames of about 100 feet (30 meters) high.
The cause of the initial blast was not clear. The Xinhua News Agency said it happened while a Liberian tanker was unloading oil at the port. It said the tanker left safely.
A vast stretch of polluted sea remains the next challenge. About 20 boats were trying to clean up a dark brown slick of oil and pollution at least 50 square kilometers (19 square miles) in size off Dalian's Xingang Harbor, Xinhua said Saturday night.
The fire raged for more than 15 hours after two oil pipelines exploded in the port of Dalian in northeast China
The pipelines are owned by China National Petroleum Corp., which is Asia's biggest oil and gas producer by volume.
The state-owned company did not immediately comment. Phones at its Beijing headquarters rang unanswered, and while the company website showed updates Saturday, there was no mention of the fire.
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