A blue whale that was spotted last week entangled in fishing wire off the Southern California coast might have moved hundreds of miles south to Mexico, still towing a line and a red buoy, officials said on Monday.

The U.S. Coast Guard said a vessel reported seeing a blue whale tangled in fishing line near the Coronado Islands, off the coast of Mexico just south of the California border, according to Jim Milbury, a spokesman for the National Oceanic and Atmospheric Administration.

“We believe this is the same whale that was entangled off Palos Verdes,” Milbury said. “The description fits.”

Last week, a blue whale was seen towing hundreds of feet of wire with a buoy attached near the coast of the upscale seaside community of Rancho Palos Verdes, south of Los Angeles.

Whale watching ships were dispatched Sunday to look for the massive mammal and attempt to free it from the tethers, which could eventually weaken or kill it, NOAA said.

NOAA officials would be able to respond to the whale if it moves back into U.S. waters, Milbury said. Mexican rescue teams have been contacted, he said.

Blue whales, the largest mammals on Earth, can reach nearly 100 feet (30.3 meters) in length and weigh 190 tonnes. They were once driven to near extinction by whaling.

(Reporting by Victoria Cavaliere; Editing by Cynthia Osterman)