Washington (CNN) Eighteen US Marines and one sailor were arrested Thursday for alleged involvement in various illegal activities ranging from human smuggling to drug-related offenses, according to a statement made to CNN from the Naval Criminal Investigative Services.

The arrests took place in a dramatic fashion on Thursday morning at Camp Pendleton, California, during a battalion formation.

"Information gained from a previous human smuggling investigation precipitated the arrests," a statement from the Marine Corps said. "None of the Marines arrested or detained for questioning served in support of the Southwest Border Support mission."

Eight other Marines were also questioned on their involvement in alleged drug offenses unrelated to today's arrests, the Marine Corps said.

A US official told CNN that Thursday's arrests are related to an incident that occurred earlier this month in which two Marines from Camp Pendleton were charged with transporting undocumented immigrants for financial gain.

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