Iran vessels harass another US Navy ship in Persian Gulf, defense officials say

Iranian vessels from its Revolutionary Guard Corps harassed another U.S. Navy ship Sunday in the central Persian Gulf, a defense department official tells Fox News.

USS Firebolt, a coastal patrol ship, was shadowed by seven Iranian vessels. Three of the vessels came within 500 yards and shadowed Firebolt for eight minutes. Then one of the Iranian vessels broke off and raced in front of Firebolt and "came to a stop directly in front of the ship" at a range of 100 yards, according to the official.

The U.S. Navy ship attempted multiple radio communications with the Iranian vessel, but there was no reply.

The U.S. ship took evasive action to "narrowly avoid" the Iranian ship which stopped directly in front of it, according to the official.

"Clearly the Iranian behavior has to change," Capt. Jeff Davis, a Pentagon spokesman, said Tuesday.

Davis refused to outline any specifics on how to bring about that change.

The U.S. Navy assessed the interaction as "provocative harassment."

The Iranian ship had its weapons manned, but not pointed at the U.S. Navy ship, according to a defense official.

There have bene 31 "unsafe and unprofessional" interactions with Iran and the U.S. Navy. Each time, Iran was the aggressor Navy officials said. There have been nearly twice as many cases of harrassment by Iranian vessels against the U.S. Navy in the first half of 2016 as the first half of 2015.

Fox News was first to report that Iranian harassment of U.S. Navy ships in the Gulf have doubled in the past year.

This latest incident follows four similar provocations late last month, one which resulted in warning shots being fired by a U.S. Navy ship when an Iranian vessel approached quickly and at close range.