The U.S. military said Tuesday that an Islamic Revolutionary Guard Corps Navy boat came within 150 yards of American warships in the Strait of Hormuz, but the situation was de-escalated with the help of audible warnings and non-lethal use of lasers.

In a statement, the U.S. military said the incident took place on December 5 during a routine transit in international waters.

“The IRGCN’s actions violated international standards of professional and safe maritime behavior, increasing the risk of miscalculation and collision,” the statement said.