The United States and Britain on Sunday blamed Iran for a drone attack last week on an oil tanker off the coast of Oman that killed two people.

"We are confident that Iran conducted this attack," U.S. Secretary of State Antony Blinken said in a statement, while accusing Tehran of increasingly deploying the armed drones throughout the region.

The top U.S. diplomat said there was "no justification" for the attack in the north Arabian Sea on the Mercer Street oil tanker, a ship managed by London-based Zodiac Maritime that is owned by Israeli billionaire Eyal Ofer.

Blinken said the attack threatens "freedom of navigation through this crucial waterway, international shipping and commerce, and the lives of those on the vessels involved."

He said the U.S. is consulting with allies and governments in the Middle East "on an appropriate response, which will be forthcoming."

British Foreign Secretary Dominic Raab said, "We believe this attack was deliberate, targeted, and a clear violation of international law by Iran."

He said one or more drones was used in the attack.

No one has claimed responsibility and earlier Sunday, Iranian Foreign Ministry spokesman Saeed Khatibzadeh said allegations that Iran carried out the attack were "baseless."

The U.S., Britain and Israel have yet to display physical evidence from the strike or other information indicating why they blame Iran.

Israel also blames Iran and Israeli Prime Minister Naftali Bennett has threatened retaliation.

"We know, at any rate, know how to convey the message to Iran in our own way," Bennett said.

The drone attack ripped a hole through the top of the oil tanker's bridge, where the captain and crew commanded the vessel, a U.S. official said.

The U.S. Navy said the American nuclear-powered aircraft carrier USS Ronald Reagan and the guided missile destroyer USS Mitscher escorted the Mercer Street as it headed to a safe port. On Sunday, satellite-tracking information from MarineTraffic.com showed the tanker stopped off the coast of Fujairah in the United Arab Emirates.

Some information for this report came from the Associated Press and Agence France-Presse.