A suspected oil spill near Kharg Island was likely caused by a tanker dumping waste, and not by a leak from oil facilities, Reuters reported.
The oil stain, spotted on satellite imagery, spans dozens of square kilometers of sea.
According to Tanker Trackers, Kharg Island, through which 90% of Iranian oil exports pass, has not loaded any tankers since May 6 due to the leak.
Iranian Vice-President Shina Ansari claimed to Reuters that monitoring indicated that the spill was caused "by the discharge of ballast water" contaminated by substances from a foreign tanker. He also denied any leaks from Iranian facilities or pipelines.
Tanker Trackers acknowledged the plausibility of the explanation, but noted, "Ironically, this was a vessel that they had seized a long time ago."
Last month, the Wall Street Journal reported that the US launched about 50 strikes on Kharg Island in a single day.
NBC News reported that the strikes targeted Kharg Island's military facilities, including military bunkers, storage facilities, and air defense systems.
Vice President JD Vance stated that the strikes do not represent a change in strategy by the US: "I don’t think the news about Kharg Island represents a change in strategy, or represents any change for the president of the United States."