Mexican authorities found AK-47 assault rifles, powerful .50 caliber rifles and other weapons in late 2009 that were later linked to the U.S. sting operation to trace weapons going across the border to Mexico, the report said…

Of the 2,000 weapons sold to the suspected gun traffickers, just over half remain unaccounted for, the report added. The Justice Department said that the ATF was not aware of the majority of those gun sales when they occurred.

“Given the vast amount of ‘Operation Fast and Furious’ weapons possibly still in the hands of cartel members, law enforcement officials should expect more seizures and recoveries at crime scenes,” said the congressional report.