Iranian authorities are working to control an oil spill four miles (6.4 kilometres) off Iran's Kharg Island, the country's IRNA news agency reported on Wednesday.
The leak from oil pipelines was reported on Sunday and the required actions have been taken, IRNA cited a local official as saying.
"Two other spots have been identified by drones", IRNA said, adding that procedures had been activated to stop the pollution spreading and the situation was being continuously assessed.
Iran is a member of the Organization of the Petroleum Exporting Countries with production of around 3.2 million barrels per day, or about 3% of global output.
Most of Iran's oil and gas is in the south of the country, where the Kharg Island terminal is situated and from which around 90% of Iranian oil exports are shipped.
(Reuters - Reporting by Elwely Elwelly; Editing by Andrew Cawthorne and Mark Potter)