The U.S. Navy fired warning shots at a patrol boat this morning reportedly belonging to the Iranian Revolutionary Guard Corps in the Persian Gulf. U.S Defense Department officials said the boat came within 150 yards of the USS Thunderbolt, a Navy patrol ship.

also reports that the Iranians did not respond to warning shots, radio calls, “firing of flares and five short blasts from the US Navy ship’s whistle, which is the internationally recognized communications signal for danger.” At the time of the shooting, the Thunderbolt, a Cyclone-class patrol boat, was escorted by the USS Vella Gulf, a 567-foot long guided missile cruiser, and two U.S. Coast guard vessels.

The Thunderbolt is normally armed with a pair of 25mm Mk-38 machine guns, two automatic grenade launchers, and two .50-caliber machine guns. Not to mention all of the heavy weaponry on the Vella Gulf, a Ticonderoga-class cruiser which usually stands guard over aircraft carrier battle groups.

Concerned about a collision, the U.S. Navy fired warning shots into the waters near the Iranian boat. The vessel eventually stopped, but stayed in the area for several hours, according to the Defense Department.

But these close and dangerous encounters aren’t remotely rare.

Back in June, the U.S. claimed an Iranian boat aimed a laser on a U.S. helicopter accompanying a formation of American ships in the Strait of Hormuz, at the mouth of the Persian Gulf. The U.S. Navy also alleged that the Iranian Islamic Revolutionary Guard Corps acted provocatively in April while it approached the USS Mahan, an American destroyer, in the Persian Gulf. No warning shots were fired.

That wasn’t the case in January, when the Mahan fired warning shots after five Iranian vessels approached the destroyer and two other U.S. entering the Strait of Hormuz.

In 2016 alone, there were 35 cases of “unsafe or unprofessional” behavior by Iranian vessels in 2016, according to U.S. Navy Capt. Jeff Davis, a Pentagon spokesman. Most took place during the first part of the year.

Though, there is some good news. The number of encounters between Iranian and U.S. vessels in 2017 so far isn’t nearly as high as last year, according to a U.S. official who spoke with CNN.