A sanctioned tanker loaded with crude is leaving a growing trail of oil in protected waters off the coast of Oman, according to newly reviewed satellite images, as experts warn the stranded vessel could break apart during the region's rough monsoon season.

Satellite images reviewed by The Associated Press show an oil sheen covering roughly 20 square kilometers, or about 8 square miles, around Dhofar's Qibliyah Island, part of Oman's protected Hallaniyat Islands. Dark patches of crude have also reached the shoreline. Experts say the leak has worsened in recent days, fueling fears that rough weather could trigger a much larger spill.

"The last few days, the imagery indicates an increase in oil coming out, as the size of the sheen is growing," Wim Zwijnenburg, an environmental expert with the Dutch peace organization PAX, told the AP.

He said the biggest risk is that the vessel could break apart as strong winds and rough seas during the annual monsoon season continue to pound the ship's hull.

The 899-foot, Cameroon-flagged Caroline Bezengi has been stranded off Oman's southern coast since June after its crew reported an onboard explosion, according to maritime news outlets. Reuters, citing maritime security sources, reported the vessel first ran into trouble on June 8 near the Yemeni port of Mukalla, where initial assessments suggested a blast may have occurred. The cause has not been confirmed.

Ship-tracking data reviewed by Reuters showed the tanker had loaded Russian crude at the Black Sea port of Novorossiysk before its latest voyage. The vessel has been sanctioned by the United Kingdom, the European Union, Canada and Switzerland for allegedly transporting Russian oil as part of Moscow's so-called "shadow fleet" — a network of aging tankers used to bypass Western sanctions imposed after Russia's invasion of Ukraine.

Zwijnenburg estimated the tanker is carrying more than 800,000 barrels of crude oil and said recent imagery suggests at least one section of the hull has been breached. Other maritime specialists who reviewed the images told Reuters the vessel also appears to be listing, adding to concerns that it could eventually break apart.

The spill threatens a protected marine reserve in the Arabian Sea that is home to endangered petrels and other rare wildlife. Greenpeace Germany warned that oil has already polluted stretches of coastline and damaged the area's fragile ecosystem.

"With oil apparently continuing to leak and the tanker stranded in a difficult location, there is a serious risk of a much larger oil disaster, with even more devastating consequences for the region's coastlines and marine ecosystems," Greenpeace Germany's Nina Noelle told the AP.

The U.N.'s International Maritime Organization said earlier this week it is monitoring the situation, adding that while the vessel has not broken apart, authorities are continuing to assess the safety and environmental risks.

Oman's Ministry of Transport, Communications and Information Technology ordered the vessel's owners to remove the ship and its cargo by July 23. It is unclear whether that deadline was met or whether the owners have responded.