SAN DIEGO — Authorities on Wednesday are in South Mission Beach after about 15 people arrived on a boat off the coast in what appears to be a mass migration effort, fire officials said.

The U.S. Coast Guard received a call from San Diego lifeguards around 3:30 p.m. of individuals jumping off a boat at the south end of Mission Beach, Petty Officer Alex Gray told FOX 5.

Several lifeguard vessels responded to the scene as well as the U.S. Coast Guard and possibly a U.S. Customs and Border Protection vessel, said Mónica Muñoz with the San Diego Fire-Rescue Department.

Five men, all Mexican Nationals, were arrested, CBP confirmed. The boat was also seized by federal customs.

Other people aboard the boat ran east towards homes located along Mission Boulevard, a Border Patrol official said.

A small U.S. Coast Guard boat was used to do a shoreline search to make sure no one else was in the water. No injuries were reported, according to Muñoz.

According to an eyewitness named Matt, he and his girlfriend were in the parking lot having lunch when six people ran by them.

“They all looked soaking wet, and then they just jumped into the rocks by the jetty and started hiding. And then all of a sudden we hear sirens and a couple of police officers yelling ‘police’ and a couple of them got arrested, but it looks like some missing as well,” Matt said.

Earlier Wednesday, agents from the U.S. Border Patrol found 17 abandoned life vests aboard a boat that washed ashore on a beach in Carlsbad, per authorities.