An oil pipeline in western Iran exploded in the early hours of Friday, which led to shutting flows of up to 4,000 barrels per day, the semi-official Mehr news agency quoted an official as saying, without giving more details on the incident.
The explosion occurred at 1:30 a.m. local time (2100 GMT) in Khuzestan province, said Hormoz Qalawand, executive director of the National Iranian South Oil Company.
Mehr had previously reported the blast had happened in neighbouring Lorestan province.
"So far it is not clear if the incident happened due to technical problems or a terrorist act," he said.
Qalavand said crude flows to the oil city of Ahvaz had been halted. The pipeline had the capacity to transfer up to 4,000 barrels per day, he said. The fire, which had spread for 300 metres with flames 40 metres high, had been extinguished, Mehr reported.
Pipeline blasts are common in Iran and are often attributed to saboteurs. Last week, an explosion halted gas exports to Turkey, something authorities blamed on Kurdish rebels.
Iran is the world's fourth-largest oil producer and sits on the world's second largest natural gas reserves. The economy is heavily dependent on oil and gas revenues.