Oil leaking from the grounded tanker Caroline Bezengi has reached Oman's mainland coast, Reuters reported, citing the International Maritime Organization (IMO).

An IMO spokesperson said the oil slick is drifting northeast of Jazirat al-Kibliya island, with some contamination already reaching the mainland. Omani authorities have activated their spill response plan, estimating the slick's area at nearly 400 square kilometers.

The leak has been ongoing for some time, and seasonal monsoon winds are hampering access to the vessel, delaying salvage operations. The ship lies about 22 nautical miles (approximately 41 kilometers) from the fishing village of Sharbitat.

The Caroline Bezengi was carrying about 800,000 barrels of Russian oil destined for Asia. The 159,168-deadweight-tonne, 274-meter-long tanker ran aground in June after a series of explosions, the cause of which has not been officially established. The OSINT project Russian Forces Spotter suggested the vessel may have struck magnetic mines.

The Insider reported on the ongoing leak as early as July 31, when Greenpeace analysts, at the outlet's request, examined satellite images of the accident site. By August 6, Greenpeace estimated the slick had grown to 600 square kilometers. The discrepancy with IMO figures stems from differences in dates and assessment methods.

The tanker sits near the protected Hallaniyat Islands marine reserve, home to rare coral reefs, sea turtle nesting sites, humpback whales, and Socotra cormorants. Due to rough seas, the vessel could release tens of thousands of tonnes of the oil still on board.

The Insider reports that the Caroline Bezengi is part of a group of vessels linked to Cyprus-based Lagosmarine Ltd, which regularly shipped Russian oil from Primorsk, Ust-Luga, and Kozmino to India and China. The tanker is under sanctions from the European Union, Switzerland, Ukraine, the United Kingdom, and Canada. According to Reuters, one reason the vessel has not yet received assistance is its sanctioned status.

John Amos, CEO of the nonprofit SkyTruth, told Reuters he sees no signs that other vessels have approached the tanker to stabilize it and remove the remaining cargo. He said the oil tank could split at any moment, spilling all its contents into the sea.