0325 GMT January 21, 2021
The cause of the spill, which occurred on Wednesday, is under investigation, Siavash Arjmandzadeh, the director general of ports and maritime in Iran's Bushehr Province, told IRNA.
The cleanup took place near the Abouzar field, Iran's main production area in the Persian Gulf, Reuters wrote.
An Iranian official had told IRNA on Thursday that it was difficult to determine the cause of the spill because there were several fields belonging to Iran and other countries in the region.
He said oil could have leaked from underwater pipelines.
Abouzar oilfield, about 75km west of Iran's Kharg Island, has three main platforms producing between 195,000 and 220,000 barrels per day of oil, IRNA reported, adding 107 wells had been drilled in the field, of which 67 still operated.