U.S. says Russian planes buzzed Navy ship in Baltic Sea

A Russian Su-24 bomber lands at Hemeimeem air base in Syria, on Jan. 20, 2016. (Vladimir Isachenkov / AP)

WASHINGTON -- Russian attack planes buzzed a U.S. Navy destroyer in the Baltic Sea multiple times Monday and Tuesday, coming as close as an estimated 30 feet (9 metres) from the ship and twice passing below the ship's navigation bridge, U.S. officials said Wednesday.

The Russian Su-24 planes appeared unarmed but on Tuesday flew what the commander of the USS Donald Cook deemed to be a simulated attack profile. The Cook's commander judged the actions unsafe and unprofessional, but the ship took no action beyond trying unsuccessfully to communicate with the aircraft by radio, according to a statement by U.S. European Command.

"We have deep concerns about the unsafe and unprofessional Russian flight manoeuvrs," the statement said. "These actions have the potential to unnecessarily escalate tensions between countries, and could result in a miscalculation or accident that could cause serious injury or death."

The statement said the Cook was conducting deck landing drills with an allied military helicopter when two Su-24s made numerous close-range, low-altitude passes Monday afternoon. One pass occurred while the helicopter was refuelling on the Cook's deck.

"As a safety precaution, flight operations were suspended until the Su-24s departed the area," the statement said.

European Command did not identify the ally involved, but other officials said the helicopter was Polish.

The European Command statement said U.S. officials are using diplomatic channels to address the matter. The incidents also are under review by the Navy.

It was unclear if the U.S. government would formally protest the Russian actions, which come at a time of tensions between Washington and Moscow over Russia's annexation of Crimea, its military intervention in eastern Ukraine and fears among former Soviet states in eastern Europe that Russian aggression could threaten their independence.

White House press secretary Josh Earnest said the incident was part of a pattern of unsafe Russian aircraft action.

"This incident ... is entirely inconsistent with the professional norms of militaries operating in proximity to each other in international waters and international airspace," Earnest said.

"There have been repeated incidents over the last year where the Russian military, including Russian military aircraft, have come close enough to each other or have come close enough to other air and sea traffic to raise serious safety concerns. We continue to be concerned about this behaviour," he said.

European Command released a Navy photo showing one Su-24 soaring past the Cook at close range.

A Navy video clip shows another low-altitude pass with a U.S. sailor shouting, "Below the bridge wing," meaning the Russian plane was flying below the level of the Cook's navigation bridge.

The incident began Monday with a pair of Russian Su-24 planes making 20 close passes over the Cook, coming as close as 1,000 yards at an altitude of about 100 feet, according to a U.S. defence official. The official was not authorized to discuss some details by name and spoke on condition of anonymity.

On Tuesday, a Russian KA-26 submarine-hunting helicopter circled the Cook at low altitude seven times, taking photographs, the official said. About 40 minutes later, another pair of Su-24 attack planes, apparently unarmed, buzzed the Cook 11 times, the European Command statement said. At one point, at least one of the planes came within 30 feet of the ship, according to a Pentagon spokeswoman, Lt. Col. Michelle L. Baldanza.

The U.S. believes the Russian actions may have violated a 1970s agreement meant to prevent unsafe incidents at sea. The agreement was between the U.S. and the former Soviet Union but remains in force with Russia.

Officials said the Cook was operating in international waters 70 nautical miles off the Russian enclave of Kaliningrad. It had departed the Polish port of Gdynia on Monday. In April 2014, the Cook reported what it considered provocative actions by an apparently unarmed Russian Su-24 jet that made numerous low passes near the ship in the Black Sea near Romania.