Iranian authorities are tackling an oil spill 6.4 km off its main crude export terminal.
Iran’s IRNA news agency said the incident occurred on Sunday off Kharg Island.
The oil came from subsea pipelines and the “required actions” have been taken, IRNA cited a local official as saying.
“Two other spots have been identified by drones,” IRNA added.
The report said procedures had been activated to stop the pollution spreading.
The situation is being continuously assessed, it added.
About 90% of Iran’s oil exports are shipped from the terminal.
The Tasnim news agency said two slicks were spotted, citing Mohammad Shakibi-Nasab, director general of the regional ports and maritime organisation.
Analytics company Kpler said it is unclear if tanker loadings would be affected.
Iranian tanker shipments had plunged nearly 70% in the first 10 days of October over fears of Israeli retaliation for Iran’s missile attack.
State-owned National Iranian Tanker Co moved vessels away from its key export terminal on Kharg Island in the period.
Data obtained by Iran International suggests the country loaded only 600,000 barrels per day in the first 10 days of the month, down from an average of 1.5m bpd in recent months.
Tracking data shows an increase in tanker numbers at the Kharg terminal since 10 October.
Loadings have resumed, but are slower than usual. Export volumes are now estimated at 800,000 bpd.
Reports have since claimed Israel will not target Iran’s oil terminals.
