Sixteen US Marines were arrested at Camp Pendleton in California on Thursday during battalion formation for alleged illegal activities ranging from human smuggling to drug-related offenses, the Marine Corps said.

Eight other Marines were questioned about their involvement in unrelated drug offenses, according to the 1st Marine Division.

None of the Marines were supporting operations along the US-Mexico border, the USMC said.

The 16 suspects range in rank from private first class to corporal, or E-2 to E-4, according to 1st Lt. Cameron Edinburgh, a division spokesman.

Edinburgh told the San Diego Union-Tribune the arrests were made during formation at the unit’s parade deck in the San Matteo area of the base.

“It was a public display for the entire unit to see,” he told the newspaper.

Their names and details of their alleged offenses were not immediately released.

“Information gained from a previous human smuggling investigation precipitated the arrests,” the division said in a statement.

The mass arrests follow the July 3 arrest by Border Patrol agents of two Marines — Lance Cpl. Byron Darnell Law II and Lance Cpl. David Javier Salazar-Quintero — about 20 miles east of the Tecate port of entry.

The two riflemen, who were assigned to 1st Battalion, 5th Marine Regiment, 1st Marine Division at Camp Pendleton, allegedly smuggled three undocumented immigrants for financial gain, according to the Marine Corps Times.

They face one felony count each of seeking monetary compensation for moving unauthorized immigrants into the US after they had crossed the border, according to the Union-Tribune.

The unauthorized immigrants told authorities they had made arrangements to be smuggled into the US and had been told via cellphone to get into a vehicle driven by Law, according to a complaint.

They told authorities they were Mexican citizens, had no immigration papers and were not permitted to enter the US, the complaint said.

Two of the migrants said they agreed to pay $8,000 to be smuggled into the country, the complaint said. One planned to reach Los Angeles and the other wanted to travel to New Jersey.

The two Marines are recipients of the National Defense and Global War on Terrorism service medals.

First Marine Division officials and the Naval Criminal Investigative Service carried out Thursday’s dramatic arrests.

“1st Marine Division is committed to justice and the rule of law, and we will continue to fully cooperate with NCIS on this matter,” the statement says.

“Any Marines found to be in connection with these alleged activities will be questioned and handled accordingly with respect to due process.”

More than 42,000 active duty personnel work at Camp Pendleton, which is located on the coast near Oceanside, California, and also hosts thousands of Marine reservists for annual training.