July 16 (UPI) -- A Panama-flagged oil tanker based in the United Arab Emirates appeared to switch off its transponder in the Strait of Hormuz on Saturday and has not been heard from since, according to ship-tracking data.
The Riah's last known position was near the coast of Qeshm, a small Iranian island in the Strait of Hormuz. Information about the ship indicated that it was traveling to Sharjah in UAE before turning sharply and stopping in Iranian territorial waters, the Washington Post reported.
Georgios Hatzimanolis, of the ship-tracking website MarineTraffic.com, said the Riah has not reported a position since Saturday.
"From what I can see the vessel has been almost exclusively operating in the UAE for the last year, traveling between Sharjah and Fujairah," Hatzimanolis told Al Arabiya English. "It is owned by Prime Tankers, which operates out of Dubai, and is insured by West England P&I."
This missing tanker highlights high tension in the region. On June 13, the U.S. Navy responded to separate distress signals after attacks on the Japanese-operated Kokuka Courageous and the Norwegian-flagged MT Altair in the Gulf of Oman.
Secretary of State Mike Pompeo blamed Iran for those and previous attacks on oil tankers in the region.
An Iranian tanker was seized by the Royal Marines July 4 because it was accused of carrying crude oil to Syria against European sanctions. Iran warned that it would retaliate if it was not released.
Five Iranian gunboats failed to detain a British oil tanker in the Persian Gulf on July 10.
One official said the Riah has not sent out a distress call. Lt. Christina Gibson, spokeswoman of the Bahrain-based U.S. 5th Fleet said that they are aware of the missing ship but said she had no additional information.