Iran said the accusations were part of a campaign of American disinformation and “warmongering.” The U.S. also blamed Iran for similar attacks last month against four tankers in the same waterway, a vital route for a third of the world’s petroleum.

Watch: The Pentagon on Thursday night released a video that it says shows an Islamic Revolutionary Guards Corps boat pulling alongside one of the damaged ships and removing an unexploded mine. The Guard Corps is an elite branch of Iran’s military.

Another angle: The Japanese operator of one of the ships said today that it was struck by a flying object, disputing at least part of the U.S. account.

What’s next: President Trump faces difficult choices after saying Iran would “suffer greatly” if American interests were threatened. But he has been vague about what his response might be, and his administration is divided.