(CNN) -- A trio of Democratic U.S. senators called for tougher firearms laws and regulations after releasing a report that showed a large number of weapons used by Mexico drug gangs originating north of the border.
More than 70% of 29,284 firearms submitted to the U.S. Department of Alcohol, Tobacco and Firearms for tracing by the Mexican government during 2009 and 2010 originated in the United States, according to the report.
"Congress has been virtually moribund while powerful Mexican drug trafficking organizations continue to gain unfettered access to military-style firearms coming from the United States," said Sen. Diane Feinstein of California.
Feinstein was joined in her call by Senators Charles Schumer, D-New York, and Sheldon Whitehouse, D-Rhode Island.
In a letter this month to Feinstein, the ATF acknowledged that the United States keeps no record of criminal firearms seized in Mexico and that "the Mexican government does not submit every recovered firearm to ATF for tracing."
As a result, the ATF-provided figures may not be representative of all firearms recovered by Mexican officials.
"This report confirms what many of us already know to be true ... it is still too easy for Mexican drug lords to get their hands on deadly military-grade weapons within our borders," said Schumer. "We need to redouble our efforts to keep violent firearms out of the hands of these traffickers."