Multiple Chinese military ships were spotted by the U.S. Coast Guard in the waters off Alaska, officials said in a news release on Wednesday. 

Three vessels were detected about 124 miles north of the Amchitka Pass in the Aleutian Islands, and a fourth ship was spotted about 84 miles north of the state’s Amukta Pass. The ships were seen on Saturday and Sunday. 

All four ships were in international waters, the Coast Guard said, but were inside the U.S. Exclusive Economic Zone, which extends 200 nautical miles from the U.S. shoreline. In these areas, the United States has exclusive rights for exploring and using marine resources. 

All four ships “operated in accordance with international rules and norms,” according to Rear Admiral Megan Dean, the Coast Guard district commander. 

When contacted by the Coast Guard to “ensure there were no disruptions to U.S. interests in the maritime environment around Alaska,” the Chinese vessels said that they were in the area for “freedom of navigation operations,” Dean said. 

The naval presence was tracked by the U.S. Coast Guard Cutter Kimball, a 418-foot-long national security vessel that has previously conducted joint exercises in the Indo-Pacific region. The cutter is in the area as part of Operation Frontier Sentinel, a Coast Guard exercise “designed to meet presence with presence when strategic competitors operate in and around U.S. waters,” according to the agency. 

The Kimball monitored all of the Chinese vessels until they left the U.S. Exclusive Economic Zone, officials said, and the ship  will continue to patrol the zone. 

Similar incidents have occurred in recent years. In September 2021 and September 2022, Coast Guard cutters in the area encountered Chinese surface action groups, and in August 2023, the U.S. Navy sent four destroyers to the Alaskan coast after 11 Chinese and Russian warships were spotted patrolling in international waters within the Exclusive Economic Zone.