An oil slick stretching roughly 600 square kilometres has spread along the coast of southern Oman, threatening a protected marine reserve, after a tanker suspected of belonging to Russia's so-called shadow fleet ran aground following a series of unexplained explosions at sea. Environmental organisations Greenpeace and Dutch NGO PAX have raised the alarm over what they warn could become a major regional ecological disaster.

The vessel, believed to be the Caroline Bezengi, is thought to have been loaded with crude oil at the Russian Black Sea port of Novorossiysk and was reportedly heading to India when it experienced at least three explosions on 6 June. The ship stopped transmitting its AIS location signal on 11 June and subsequently drifted until it ran aground off Oman's southern coast. Satellite imagery analysed by Greenpeace shows the oil slick grew significantly between 24 July and 4 August 2026, already reaching large stretches of shoreline around the uninhabited island of Al-Qibliyah. The tanker is estimated to be carrying around 110,000 tonnes of crude oil — approximately one million barrels — and oil has been detected as far as 40 kilometres from the grounded vessel.

The spill is particularly alarming because of where it is occurring. The Al-Hallaniyat archipelago, a group of islands off Oman's southern coast, sits within a marine protected area established in 2025. The reserve is home to coral reefs, seagrass beds, nesting seabirds, sea turtles, dolphins, and the rare Arabian Sea humpback whale — a critically endangered population found only in this region.