President Donald Trump on Saturday issued new threats at Iran, including one that could amount to a war crime if carried out.

Trump warned Iran that a strike on “any Americans” or “American assets” would result in the US hitting 52 targets – including “Iranian culture” sites.

But deliberately targeting cultural sites or cultural heritage sites could amount to a war crime under international law.

Visit Business Insider’s homepage for more stories.

President Donald Trump on Saturday warned Iran that a strike on “any Americans” or “American assets” in retaliation for the killing of its top general would result in the US targeting 52 sites – including “Iranian culture” sites.

But deliberately targeting cultural sites or cultural heritage sites could amount to a war crime.

The US killed Maj. Gen. Qassem Soleimani, Iran’s top military leader, in a drone strike in Baghdad on January 3. Iran has vowed to retaliate, with Iranian President Hassan Rouhani on Saturday stating that the US had committed a “grave mistake.“

A day after the president claimed Soleimani’s killing was meant to “stop a war” rather than start one, he tweeted: “Let this serve as a WARNING that if Iran strikes any Americans, or American assets, we have targeted 52 Iranian sites (representing the 52 American hostages taken by Iran many years ago), some at a very high level & important to Iran & the Iranian culture, and those targets, and Iran itself, WILL BE HIT VERY FAST AND VERY HARD. The USA wants no more threats!”

Under international law, destroying cultural sites during armed conflict could be designated a war crime.

United Nations resolution 2347 condemns “the unlawful destruction of cultural heritage, including the destruction of religious sites and artefacts, and the looting and smuggling of cultural property from archaeological sites, museums, libraries, archives, and other sites, notably by terrorist groups.”

Lees ook op Business Insider Dit cijfer plakken ondernemers uit 12 sectoren op hun vooruitzichten voor de komende 6 maanden

And under Protocol I of the Geneva Conventions it is prohibited to “commit any acts of hostility directed against the historic monuments, works of art or places of worship which constitute the cultural or spiritual heritage of peoples…to use such objects in support of the military effort…[and] to make such objects the object of reprisals.”

In 2016, judges at the International Criminal Court issued a nine-year sentence to a radical Islamist who had destroyed shrines in Timbuktu, Mali, in 2012. This marked the court’s first prosecution of the destruction of cultural heritage as a war crime, The New York Times reported at the time.

The US Department of Defense Law of War Manual also touches on these matters, discussing the “protection of cultural property” at length.

When contacted by Insider for more information on Trump’s tweet and the reference to “Iranian culture” sites, a Pentagon spokesperson said: “We would refer you to the White House concerning this tweet.”

The White House did not offer a comment in response to a query from Insider on Trump’s tweet.

Trump’s tweet threatening Iran garnered a fair amount of attention on Twitter, including from members of Congress.

Democratic Rep. Alexandria Ocasio-Cortez excoriated the president, tweeting, “This is a war crime. Threatening to target and kill innocent families, women and children – which is what you’re doing by targeting cultural sites – does not make you a ‘tough guy.’ It does not make you ‘strategic.’ It makes you a monster.”

Sen. Chris Murphy of Connecticut also weighed in on Trump’s threat, calling it a “moment we all feared” in a tweet.

“An unstable President in way over his head, panicking, with all his experienced advisers having quit, and only the sycophantic amateurs remaining. Assassinating foreign leaders, announcing plans to bomb civilians. A nightmare,” he wrote.