A Panamanian-flagged oil tanker last seen near the Strait of Hormuz may have been seized by Iranian naval forces.

The MT Riah went missing after entering Iranian waters over the weekend, according to ship tracking data. U.S. intelligence officials believe it may have been forced into Iranian territory by members of Iran’s Islamic Revolutionary Guard Corps Navy, according to CNN. Some reports claim the Riah belonged to the United Arab Emirates, but a UAE official denied that claim on Monday.