LOS ANGELES — Four U.S. Marines have been arrested for allegedly selling rifles and assault weapons to gang members in Los Angeles.

Federal and state authorities told the Los Angeles Times that the investigation has been going on for several weeks and that it involves allegations that the Marines sold guns to gang members operating in the San Fernando Valley.

The suspects face state weapons charges, the sources said.

The sources, who spoke on condition of anonymity because the case is ongoing, said officials plan to release more details about the case soon.

The arrests come several days after federal officials served search warrants at a home in San Clemente. At the time, officials declined to say what the probe was about. The San Clemente Times took photos showing boxes full of weapons apparently seized from the house, including large military-style weapons.

It’s unclear how many weapons were involved or where the Marines were stationed. Officials did not immediately identify which gang purchased the weapons or how many gangs may have been involved.

The case was investigated by the Bureau of Alcohol, Tobacco, Firearms and Explosives; the Los Angeles Police Department; the Naval Criminal Intelligence Service; and the U.S. Postal Service Office of Inspector General, as well as officials from the Marine Corps.

The arrests were made Monday. More arrests are possible, the sources said.