Federal agents have arrested three retired Marines suspected of selling illegal assault weapons to a notorious Los Angeles street gang, authorities said Tuesday.

The suspected ringleader, Adam Gitschlag, who served in Iraq and was once based at Camp Pendleton, was arrested at his Orange County home Nov. 2 as part of an operation carried out by the Bureau of Alcohol, Tobacco, Firearms and Explosives, as well as military investigators and local police.

The arrests were announced a week after a Navy SEAL in San Diego and two others were charged with smuggling machine guns from Iraq for sale on the black market.

Investigative documents state that Gitschlag oversaw the sale of two cases containing firearms, including an AK-47, two Russian and Romanian variants of the weapon and two other semiautomatic rifles.

Under California law, it is illegal to own or sell unregistered assault weapons.

Reached on his cell phone, Gitschlag said the charges are "definitely untrue," and that he is a private weapons collector and patriot who has worked hard to serve his country.

"I did not sell any gang members any weapons," he said. "I love my country with all my heart. I would never expect my government to do this."

The ATF says the deal was carried out June 23 in the parking lot of a Pasadena post office. Gitschlag, along with another former Marine, met with a postal service supervisor, a Florencia 13 street gang member and other associates, and sold them the weapons for $6,000, the ATF said.

Unbeknown to Gitschlag, one of the men was working as an ATF informant.

In front of the F-13 gang member, the informant asked Gitschlag if he would be willing to sell more firearms to other gang members in the future. He agreed, according to a search warrant affidavit.

The gang member never took possession of the weapons, and the informant gave them to ATF agents after the sale.

On Monday, ATF agents arrested Jose Smith Pacheco, 31, of Montebello, and Miguel A. Ortiz, 49, of Northridge, both former Marines.

Also arrested were Edwin Cano, 33, of Northridge, and Christopher John Thomas, 32, of Van Nuys.

All five defendants are charged with five counts each of having unlawful assault weapons. Cano faces additional counts of being a felon in possession of a firearm.

On Nov. 3, authorities arrested three men, including an active duty U.S. Navy SEAL, for conspiring to smuggle and sell weapons to an undercover federal agent in Nevada and Colorado.

According to a criminal complaint, SEAL Nicholas Bickle of San Diego smuggled 80 AK-47 weapons from Iraq or Afghanistan, including factory-made 7.62 mm Iraqi machine guns that would be difficult or impossible to trace. Other weapons included Ruger handguns of the type used by U.S. military police officers.

In Gitschlag's case, investigators were still trying to determine where the guns came from, but several were purchased at gun shows in Arizona, ATF spokesman Chris Hoffman said.

Florencia 13 is a long-established Latino street gang which has grown to control large swaths of South Los Angeles. The gang has been blamed for numerous homicides, including the racist killings of black residents.

John Torres, the ATF's special agent in charge of the Los Angeles area, declined to comment on details of the ongoing investigation but said "it is a shame that these individuals took an oath to protect the nation, but placed the communities at risk by allegedly selling illegal high-powered firearms to gang members."

Stunned neighbors stood at the end of Gitschlag's driveway as agents raided his house last week. Boxes of ammunition and dozens of pistols and rifles were hauled out the building, including camouflaged, tactical-looking rifles with high-power scopes. In all, authorities seized more than 20 handguns and 45 rifles and shotguns, as well as 4,000 rounds of ammunition.

Gitschlag said most of his weapons were antiques, and he denied having any assault rifles.

Gitschlag left the Marines in 2005 after serving in Fallujah. He said he is a disabled combat vet.