Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

LOS ANGELES — Six people were arrested in Australia on Thursday and Friday after U.S. investigators intercepted almost two tons of methamphetamine and other narcotics in Southern California bound for Australia, authorities in both countries said. It's believed to be the largest seizure of meth in U.S. history.

U.S. Customs and Border Protection said in a statement that the drugs, packed in three containers and concealed in what were labeled as loudspeakers, were intercepted at the Los Angeles/Long Beach seaport on Jan. 11.

The U.S. Department of Homeland Security and Australian Federal Police said two U.S. citizens and four Australian citizens were arrested on Thursday and Friday Australian time in the Australian states of Victoria and New South Wales.

Australian authorities said charges included possession and attempted importation of a commercial quantity of border-controlled drugs. They said search warrants were also executed in Canada, where investigators seized "a significant quantity of suspected proceeds of crime."

The 3,800 pounds of methamphetamine was concealed in containers designed to look like loudspeakers, U.S. and Australian authorities said. Australian Federal Police

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Authorities in both countries said it was the largest meth seizure in U.S. history — more than 3,800 pounds of methamphetamine, with an estimated street value of almost $1.3 billion Australian (about $900 million U.S.), as well as about 55 pounds of cocaine and about 11 pounds of heroin.

The meth alone would equal about 85 percent of all of the meth consumed in Victoria, Australia's second-most populous state, in the course of an entire year, according to figures provided by Jason Halls, the manager of Victoria operations for the Australian Criminal Intelligence Commission.

The seizure "will have a huge effect on the illicit drug market,” Halls said.

The investigation, dubbed Operation Hoth (the site of a Rebel base in the "Star Wars" movies), began when the Victorian Joint Organized Crime Task Force alerted special agents in DHS's Homeland Security Investigations division about a planned large-scale importation of drugs by a drug smuggling group in California, Australian police said.

The investigation eventually expanded to include the U.S. Drug Enforcement Administration; the Coast Guard; Los Angeles, Long Beach and Los Angeles port police; and the Los Angeles and Orange County sheriff's departments, CBP said.

"By stopping this, we have ensured criminals will not profit from the immense pain these drugs would have caused our community," said Bruce Hill, the Australian Federal Police's assistant commissioner for organized crime.

“If this shipment had made Australian streets it equates to something like 17 million hits of ice. We have averted a tsunami of ice to Australia."

"This is a serious warning. We now believe that Mexican cartels are actively targeting Australia."

Chief Superintendent Keith Finn, head of the Federal Serious and Organized Crime Unit of the Royal Canadian Mounted Police in British Columbia, said the interception was large enough to put a noticeable dent in the meth market worldwide.

"A seizure such as this not only helps protect the country to which the shipment was destined but has a positive impact on the international market as a whole," Finn said.