A U.S. congressional committee has reported that officials failed to inform diplomats at the U.S. embassy in Mexico about a “reckless” sting operation that allowed hundreds of guns to be smuggled into Mexico.

Tuesday's report said officials with the Bureau of Alcohol, Tobacco, Firearms and Explosives jeopardized U.S. relations with Mexico by not telling Mexico-based U.S. diplomats about “Operation Fast and Furious.”

The operation allowed Arizona gun dealers to sell AK-47 variants, .50-caliber rifles and .38-caliber revolvers to known intermediaries who would then smuggle the guns to Mexico for resale. U.S. officials hoped to trace the guns to Mexican drug cartels.

The program was shut down after U.S.-purchased weapons were found at the scene of the murder of a U.S. Border Patrol agent in December.

The committee's findings showed more than 100 guns recovered at crime scenes have been linked to the operation.

A separate report released last month by three U.S. senators said 70 percent of the nearly 30,000 firearms recovered in Mexico in 2009 and 2010 came from the United States.

Mexico has been increasingly critical of U.S. efforts to stop guns from crossing the border.

Mexican President Felipe Calderon has deployed nearly 50,000 troops in the crackdown against drug violence since he took office in late 2006. More than 37,000 people have been killed in the country's drug war since then.