JUNEAU, Alaska (AP) — A U.S. Coast Guard cutter on routine patrol around Alaska’s Aleutian Islands came across a Russian ship in international waters but within the U.S. exclusive economic zone, officials said.

The crew on the U.S. Coast Guard Cutter Alex Haley on Monday detected the vessel about 30 miles (48 kilometers) southeast of the Amukta Pass, the Coast Guard said in a Friday statement. A helicopter aircrew from Coast Guard Air Station Kodiak also spotted the vessel.

The vessel was “transiting in international waters but still inside the U.S. Exclusive Economic Zone,” which extends 200 nautical miles (370 kilometers) from the U.S. shoreline, according to the statement.

The Coast Guard vessel did not communicate with the Russian ship but followed it as it moved east, the statement said.

“We met presence with presence to ensure there were no disruptions to U.S. interests in the maritime environment around Alaska” Cmdr. Steven Baldovsky, commanding officer of the Alex Haley, said in the statement.

In July, the Coast Guard while on patrol spotted four Chinese military ships north of the Amchitka Pass in the Aleutian Islands in international waters but also within the U.S. exclusive economic zone, officials said.

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Russian and Chinese bombers later that month flew together for the first time in international airspace off the coast of Alaska, in a new show of expanding military cooperation that U.S. Defense Secretary Lloyd Austin said at the time raises concerns.

The flights weren’t seen as a threat, and the bombers were tracked and intercepted by U.S. and Canadian fighter jets. But it was the first time that Chinese bomber aircraft flew within the Alaskan Air Defense Identification Zone. And it was the first time Chinese and Russian aircraft took off from the same base in northeast Russia.