U.S. Navy Ship Harassed by Iranian Fast-Attack Boat

A U.S. Navy coastal patrol ship changed course after a fast-attack craft from Iran's Islamic Revolutionary Guard Corps came within 100 yards (91 meters) of it in the central Gulf on Sunday, two U.S. Defense Department officials said on Tuesday.

It was at least the fourth such incident in less than a month. U.S. officials are concerned that these actions by Iran could lead to mistakes.

Years of mutual animosity eased when Washington lifted sanctions on Tehran in January after a deal to curb Iran's nuclear ambitions. But serious differences still remain over Iran's ballistic missile program, and over conflicts in Syria and Iraq.

The officials, speaking on condition of anonymity, said the Iranian vessel sailed directly in front of the USS Firebolt, forcing the 174-foot (53-metre) U.S. ship to change course.

The interaction was "unsafe and unprofessional due to lack of communications and the close-range harassing maneuvering," one of the officials said, adding that uncovered and manned weapons were seen on the Iranian vessel.

The U.S. ship tried to communicate with the Iranian ship by radio three times but received no response.

The incident began when seven Iranian ships "harassed" the Firebolt, U.S. officials said.

The U.S. official said there have been 31 similar interactions with Iranian ships this year, almost double the amount from the same period last year.

"We don't see this type of unsafe and unprofessional activity from any other nation," the official added.

At the time, Iran's defense minister said Iranian vessels were just doing their job.

Last week, the head of U.S. Central Command, General Joseph Votel, told reporters that unsafe maneuvers in the Gulf were part of the Iranian regime trying to exert its influence in the region.