Iranian military gunboats with the Iranian Revolutionary Guard Corps, a designated terrorist organization, swarmed several U.S. warships on Monday that were escorting a U.S. submarine.

“Over a dozen Iranian gunboats harass formation of six U.S. warships including guided-missile submarine Georgia,” Fox News Pentagon correspondent Lucas Tomlinson said. “U.S. Coast Guard cutter fired warning shots in response in Strait of Hormuz.”

The 13 Iranian military vessels reportedly came within 150 yards of U.S. Forces, which fired 30 warning shots at the Iranian vessels. Pentagon press secretary John Kirby called the incident “significant” since previous incidents had involved fewer vessels.

The Biden administration, which is seeking to restart the nuclear deal with Iran, has offered soft words during other recent encounters where Iranian military vessels harass U.S. Forces.

Toward the end of last month, the U.S. Navy released video of Iranian military vessels harassing U.S. Forces in the Arabian Gulf.

“The activities we typically see from the IRGC Navy are not necessarily activities that are directed by the supreme leader or from the Iranian state,” U.S. Central Command’s General Kenneth “Frank” McKenzie said. “Rather [they are] irresponsible actions by local commanders on the scene. We’re very careful to ensure that we don’t get into a provocative cycle as a result of that. Luckily, our guys are pretty good … they’re very mature and they’re able to de-escalate the situation.”