Officials say a total of 19 service members have been arrested at a California Marine Corps base in connection with a migrant smuggling scandal.
The Naval Criminal Investigative Service said Friday that those arrested at Camp Pendleton include 18 Marines and one sailor, a Navy corpsman, who all serve in the same unit.
They are accused of various crimes ranging from migrant smuggling to drug-related offenses.
The case of two Marines arrested earlier this month and charged with migrant smuggling led to additional arrests.
Both are riflemen in the same unit. They have pleaded not guilty.
U.S. Border Patrol agents say smugglers lure people with offers of quick cash if they drive migrants through a heavily secured US border zone near San Diego.
An investigation has led to the arrest of 16 Marines following an investigation into human smuggling.
The Marine Corps said the arrests at Camp Pendleton, California, were carried out during a battalion formation Thursday morning at the base, north of San Diego. It is about 55 miles (90 kilometers) from the U.S.-Mexico border.
The Marine Corps said in a news release that information gained after two Marines were arrested on human smuggling charges earlier this summer led to the arrests.
Officials say the Marines are accused of various illegal activities ranging from human smuggling to drug-related offenses.
Another eight are being questioned about their alleged involvement in drug offense as part of a separate investigation.
The military says none of the Marines were involved in helping to enforce border security.