WASHINGTON — Iranian ships made reckless maneuvers close to four US warships this week in a series of incidents that could have led to dangerous escalation, defense officials said Thursday.

In one incident Wednesday, the patrol ship USS Squall fired warning shots into the water toward an Iranian vessel during a patrol in the Arabian Gulf.

‘‘These were incidents that the crews deemed unsafe,’’ Peter Cook, a Pentagon spokesman, said. ‘‘These are incidents that carry a risk of escalation and we don’t desire any kind of escalation. Our ships have been operating in that part of the world for years.

The incidents involving the Iranian ships and parts of the US Navy’s Fifth Fleet spanned multiple days and included two US patrol ships, the USS Squall and Tempest, as well as two US destroyers, the USS Nitze and Stout.


William Urban, a spokesman for the Fifth Fleet, said vessels from Iran’s Islamic Revolutionary Guard Corps conducted a ‘‘high-speed intercept’’ and passed close to the USS Nitze, an Arleigh Burke-class destroyer, in international waters around the Strait of Hormuz on Tuesday.

The Iranian ships buzzed the Nitze, ignored repeated radio, whistle, and flare warnings from the Nitze, and slowed their approach only when they were within 300 yards of the US ship, Urban said. He described the Iranian actions as ‘‘unsafe and unprofessional.’’

The Nitze was accompanied by the USS Mason, a guided missile destroyer, as it made what Urban described as a ‘‘routine transit’’ through an area that is an important international maritime thoroughfare.

‘‘The Iranian high rate of closure on a United States ship operating in accordance with international law while transiting in international waters along with the disregard of multiple warning attempts created a dangerous, harassing situation that could have led to further escalation including additional defensive measures by Nitze,’’ Urban said in a statement.


The incidents are the latest sign of US-Iranian friction near Iran’s coast. In January, a group of US sailors was detained overnight by Iranian personnel after their boats veered into Iranian waters. It was an embarrassment for the Obama administration and resulted in disciplinary action for some of the US personnel involved in that incident.

Long-standing US tensions with Iran over Tehran’s support for militant groups across the Middle East have not dissipated in the wake of a 2015 deal to curb Iran’s nuclear program. The two countries are backing opposite sides in the conflict in Syria and remain at arm’s length in Iraq despite shared support for the government in Baghdad.