The U.K. Royal Navy fended off an Iranian attempt to obstruct one of its oil tankers in the Persian Gulf by intercepting the Iranian boats with a frigate, the U.K. Telegraph reported Thursday.

The BP-owned tanker, the British Heritage, was headed into the Strait of Hormuz region when the boats from Iran’s Islamic Revolutionary Guard Corps approached the vessel.

The boats then ordered the boat to enter Iranian territorial waters nearby, one might presume for seizure; the move came after an Iranian tanker, the Grace 1, was seized by the Royal Marines last week in Gibraltar for supposedly violating sanctions on shipping oil to Syria, Sky News reported.

However, the IRGC boats were forced to withdraw after the frigate, the HMS Montrose, approached the scene and trained its 30mm guns on them.

The scene was filmed by an American aircraft that was over the scene, but the footage hasn’t been released.

“Contrary to international law, three Iranian vessels attempted to impede the passage of a commercial vessel, British Heritage, through the Strait of Hormuz,” a British Ministry of Defense representative said.

“HMS Montrose was forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away.

“We are concerned by this action and continue to urge the Iranian authorities to de-escalate the situation in the region.”

Iran had made the usual bellicose threats after the Grace 1 had been seized last week, with a deputy IRGC commander exhibiting the most bellicosity.

“Now an action that does not need ability but some stupidity has been carried out by them,” Rear Admiral Ali Fadavi, a deputy commander with the IRGC, said, Iranian state media reported.

“The American government … and also England … should not have taken action if they had made the smallest calculation,” he said.

“We had rented this ship and we carried the cargo. Their action was very silly and they will certainly regret it. Our reciprocal action will be announced.”

Meanwhile, Iranian President Hassan Rouhani merely said, “You [Britain] are the initiator of insecurity and you will realise the consequences later,” which actually sounds measured compared with Fadavi’s comments.

Tehran also denied that the showdown took place at all.

“There has been no confrontation in the last 24 hours with any foreign vessels, including British ones,” the IRGC said in a statement.

According to the Telegraph, the British Heritage had potentially anticipated the action, having taken shelter in Saudi waters along with another British-flagged ship, the Pacific Voyager.

BP, who operates the British Heritage, seemed to confirm an incident had occurred in a statement issued by the company.

“Our top priority is the safety and security of our crews and vessels,” the statement read. “While we are not commenting on these events, we thank the Royal Navy for their support.”

The ship wasn’t carrying any cargo.

So, for everyone who believed Iran when they said they weren’t about attacking tankers after the IRGC was accused of several such attacks this summer, your arguments seem a lot less plausible now — particularly since the Iranians have denied both even though the evidence on this one seems pretty clear-cut.

And if Tehran wants to make this a thing, they should probably realize that’s not going to work out well, either.

Building a navy based around fast attack vessels that can quickly swarm around a vessel is just fine if you want to harass the U.S. and/or Saudi infidels a bit. While Iran is upgrading its military capabilities in general, it’s nowhere near having the kind of naval power to play with, say, the United States or the United Kingdom. The kind of big guns on the HMS Montrose tend to win out in situations like these for obvious reasons.

These are skirmishes they’ll continue to lose, particularly since the more skirmishes there are, the more warships are going to be in the Persian Gulf region. This was not a wise decision.