WASHINGTON (AP) — Iran said Friday it seized a British oil tanker in the Strait of Hormuz, a fresh escalation in confrontations in the strategic waterway that has become a flashpoint in tensions between Tehran and the West.

The website of Iran's Revolutionary Guard, sepahnews.com, said the tanker "Impero Stena" was seized Friday for "non-compliance with international maritime laws and regulations" and was taken to an Iranian port. The report did not say what port.

The operator of the Stena Impero said it was unable to contact the ship after it was approached by unidentified vessels and a helicopter in the Strait of Hormuz. The ship has 23 crew aboard.

The British government said it was urgently seeking more information.

The incident came as Iran and the United States emphatically disagreed Friday over Washington's claim that a U.S. warship downed an Iranian drone near the Persian Gulf. American officials said they used electronic jamming to bring down the unmanned aircraft, while Iran said it simply didn't happen.

Neither side provided evidence to prove its claim.

At the White House on Friday, President Donald Trump said flatly of the Iranian drone: "We shot it down." But Pentagon and other officials have said repeatedly that the USS Boxer, a Navy ship in the Strait of Hormuz, actually jammed the drone's signal, causing it to crash, and did not fire a missile. The officials spoke on condition of anonymity to discuss sensitive technology.

Trump's national security adviser, John Bolton, said, "There is no question this was an Iranian drone, and the USS Boxer took it out as the president announced yesterday because it posed a threat to the ship and its crew. It's entirely the right thing to do."

In Tehran, the Iranian military said all its drones had returned safely to their bases and denied there was any confrontation with the USS Boxer, an amphibious assault ship.