WASHINGTON – U.S. authorities have been unable to track 1,430 of the 2,020 guns that they effectively allowed to be smuggled into Mexico as part of the failed “Operation Fast and Furious,” CNN reported.

The cable news network cited sources familiar with the investigation of Fast and Furious, an initiative launched in 2009 by the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Of the 2,020 guns involved in the ATF operation, 363 have been recovered in the United States and another 227 in Mexico, leaving more than 1,400 weapons unaccounted for, according to CNN.

The idea behind allowing the guns to be sold and smuggled into Mexico was to track them to their end-users and build criminal cases against the Mexican drug cartels, who are said to obtain much of their arsenals from gun dealers in U.S. border states.

Once Fast and Furious got under way, however, ATF agents realized they had no dependable way to keep track of the guns, which eventually began appearing at crime scenes on both sides of the border.

One of the weapons turned out to have been used in the Feb. 15 killing of U.S. immigration agent Jaime Zapata in the Mexican state of San Luis Potosi, while another Fast and Furious gun was used to kill a U.S. Border Patrol agent.

Congressional investigators said that besides failing to strike any of the drug cartels, Fast and Furious actually increased the level of violence in Mexico, where more than 40,000 people have died in drug-war mayhem since December 2006.

Amid the continuing probe of the ATF operation, the Justice Department announced Tuesday that guns dealers in Arizona, California, New Mexico and Texas will be required to report people who make multiple purchases of certain kinds of weapon.

The order covers semi-automatic rifles that use ammunition larger than .22-caliber and have a detachable ammunition clip and applies only to multiple sales to the same person within a five-day period, the department said. EFE