ANCHORAGE, Alaska (AP) — A U.S. Coast Guard ship on routine patrol in the Bering Sea came across a guided missile cruiser from China, officials said Monday.

But it turned out the cruiser wasn’t alone as it sailed about 86 miles (138 kilometers) north of Alaska’s Kiska Island, on Sept. 19.

Two other Chinese naval ships and four Russian naval vessels, including a destroyer, were spotted in single formation, the patrol boat, known as a cutter called Kimball, discovered.

The Honolulu-based Kimball, a 418-foot (127-meter) vessel, observed as the ships broke formation and dispersed. A C-130...