A US aircraft carrier entered a zone near the Strait of Hormuz being used by the Iranian navy for wargames, an Iranian official said Thursday amid rising tensions over the key oil-transit channel.

“A US aircraft carrier was spotted inside the manoeuvre zone… by a navy reconnaissance aircraft,” Commodore Mahmoud Mousavi, the spokesman for the Iranian exercises, told the official IRNA news agency.

The Iranian aircraft took video and photos of the US vessel, he added.

US officials announced Wednesday that the ship and its accompanying battle group moved through the Strait of Hormuz, a narrow stretch at the entrance to the Gulf that is the world’s most important choke point for oil shipments.