WASHINGTON — The agency that screens passengers for explosives and weapons at U.S. airport checkpoints has been handing out passes for expedited screening “like Halloween candy,” a whistleblower told a Senate committee Tuesday.

Becky Roering, a security official at the Minneapolis-St. Paul airport, testified about the “PreCheck” program run by the Transportation Security Administration at a hearing of the Senate Homeland Security Committee.

The Senate hearing was interrupted by a bomb threat, but it turned out to be a false alarm.

Under PreCheck, begun in 2011, travelers can get low-risk status for expedited U.S. screening, exempting them from, for instance, removing their shoes or opening their laptops.

Roering said enrollment in the program had fallen short, with only about a million people signed up, so the TSA started letting unapproved passengers go through the quicker PreCheck screening lines, despite the risks.

“TSA is handing out PreCheck status like Halloween candy in an effort to expedite passengers as quickly as possible, despite the self-admitted security gaps that are being created in the process,” Roering said.

About 7.2 million travelers routinely get PreCheck boarding pass stamps, many because of their affiliation with the U.S. military or other groups, said Jennifer Grover of the Government Accountability Office, also a witness at the hearing.

The hearing was focused on recent reports about failures of the TSA, an agency established after the attacks of Sept. 11, 2001, to make air travel more safe.

An undercover investigation by the Department of Homeland Security’s Inspector General found TSA screeners did not detect banned weapons in 67 of 70 tests at dozens of airports, ABC News said earlier this month.

Inspector General John Roth told the Homeland Security committee the department is investigating the leak of that report, which was classified.

Another recent report by Roth’s office said that the TSA had trouble vetting its own workers. It said TSA had failed to identify 73 of its employees with possible links to terrorism, because the TSA did not have access to all terrorism-related information from other agencies.