Investigators have intercepted almost two tons of methamphetamine in Southern California in what is thought to be the biggest meth seizure in U.S. history. The drugs are believed to have been bound for Australia and feds confirmed two U.S. citizens and four Australian citizens were arrested in the Australian states of Victoria and New South Wales between Thursday and Friday. U.S. Customs and Border Protection said the drugs, concealed in containers designed to look like loudspeakers, were intercepted at the Los Angeles/Long Beach seaport in January. The 3,800 pounds of methamphetamine has an estimated street value of about $900 million, NBC News reports, and the seizure also included 55 pounds of cocaine and 11 pounds of heroin. Bruce Hill, the Australian Federal Police’s assistant commissioner for organized crime, said: “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.”