A shipping incident in the Gulf of Oman, roughly halfway between Iran and the United Arab Emirates, has been upgraded to a “potential hijack,” according to the U.K.’s UKMTO, which monitors shipping in the region.

The event happened approximately 60 nautical miles east of the UAE port of Fujairah, the UKMTO said on its website. Investigations are ongoing, it said.

Last week, an Israeli-operated tanker was struck in a drone attack in roughly the same area, killing two crew members. The U.S., U.K. and Israel all blamed Iran and vowed to respond.