U.S. senators say security at the country's borders and ports must be strengthened after a federal investigation revealed critical gaps at two border checkpoints.
The Senate's Homeland Security Subcommittee Tuesday is hearing testimony from security officials on the need to speed up improvements in preventing dangerous materials from entering the country.
A report by Congress's investigative department says federal investigators tested security at U.S. checkpoints in December and successfully smuggled in enough radioactive material to produce two so-called "dirty bombs."
The report says border guards had detected the radioactive material using newly installed equipment, but failed to recognize that investigators used counterfeit documents to transport the material.
A Republican senator says U.S. cargo security measures now suffer from "a massive blind spot."
Some information for this report was provided by AP.