The British navy reported the "potential hijack" of a ship Tuesday in the Gulf of Oman off the coast of the United Arab Emirates.
"An incident is currently underway," the military's United Kingdom Maritime Trade Operations warned ships in the region.
"We are urgently investigating an incident on a vessel off the UAE coast," a spokesman for the British Foreign Ministry said in a statement.
Earlier Tuesday, four oil tankers, also off the coast of the UAE, reported their ships were "not under command," MarineTraffic.com reported. That usually means a ship has lost power and can longer be steered.
Last week, an oil tanker came under a drone attack off Oman that left two people dead. The United States, U.K. and Israel blame Iran for the attack.
The incidents have all taken place near the Strait of Hormuz, which is straddled by the UAE and Iran. An estimated one-fifth of the world's oil passes through the strait.
Tensions between the West and Iran have escalated recently as restoration of the Iran nuclear deal appears less likely.
There have been a series of hijackings and explosions in the area since 2019, including mine attacks the U.S. says were perpetrated by Iran.
(Some information in this report comes from The Associated Press.)