In one of the most aggressive actions in recent memory, Russian warplanes conducted “simulated attacks” on the a U.S. Navy vessel in the Baltic Sea on Tuesday, repeatedly flying within 30 feet of the ship, according to a defense official.

Sailors aboard the destroyer Donald Cook said the aircraft flew low enough to create wake in the sea waters surrounding the ship, and the ship’s commanding officer said the incident was “unsafe and unprofessional,” the defense official said.

“This was more aggressive than anything we’ve seen in some time,” according to the defense official, who spoke on condition of anonymity because U.S. officials have not officially disclosed the incidents.

Sailors aboard the ship described the Sukhoi Russian Su-24 as “wings clean,” meaning there were no visible bombs or armaments on the aircraft, the defense official said.

The nature of the overflight as a “simulated attack” may violate a 1973 treaty between the U.S. and Russia that specifically prohibits this type of maneuver, the defense official said…..