HUNTINGTON BEACH (CBSLA) – A dozen people were taken into custody Monday after they arrived on a makeshift boat in Huntington Beach, authorities said.

Huntington Beach firefighters treated 12 patients at the 16100 block of Pacific Coast Highway following what officials described as “a multi-casualty incident.”

READ MORE: Kempe's Two Goals Help Put Kings Over Oilers, 5-1

The suspects – both men and women – were taken into federal custody after they were examined by paramedics.

According to the Associated Press, nine Chinese men, a Chinese woman and two Mexican men were handed over to federal custody. One of the Mexican men is believed to be the smuggler.

READ MORE: Woman Found Shot To Death In South LA, Shooting Suspect Still At-Large

The boat first made entry via Anaheim Bay, which is U.S. Navy property, CBSLA’s Michele Gile reported.

It wasn’t immediately clear where the boat originated. The vessel will be turned over to the Naval Weapons station for further inspection.

MORE NEWS: Man Found Dead In Dumpster In South Los Angeles

Federal agents told reporters the boat was believed to belong to a smuggling operation, but didn’t offer additional details.