The US Navy said Tuesday one of its ships had again been harassed by Iranian vessels in international waters in the Persian Gulf.
The incident occurred Sunday when seven Iranian fast attack boats belonging to the Iranian Revolutionary Guard approached the USS Firebolt, a coastal patrol ship, according to Pentagon spokesman Jeff Davis.
One of the Iranian boats stopped directly in front of the Firebolt, which was only able to avoid colliding with it by making a manoeuvre, Davis said.
The crew of the US vessels tried to establish contact with the Iranians but received no answer.
"This is another example of another unsafe and unprofessional interaction we've had with the [Iranian navy] in the Gulf," Davis said.
The US Navy assessed the interaction as "provocative harassment."
There have been several similar interactions with Iranian military ships this year, according to news reports.
"This is clearly a pattern, and it's one we're not happy about, and we'd like to see this sort of behaviour stop," Davis said.