Dozens of groups are urging Congress to suspend a program that allows the transfer of surplus military equipment to state and local law enforcement agencies.

In a letter to both House and Senate leaders, the groups said they are "disturbed" by the decision of Attorney General Jeff Sessions' decision to lift the Obama-era ban on some parts of the Defense Department's program.

"We have numerous questions and concerns about the future of military-grade weapons in our communities, on our streets, and in our schools," the letter said. "We urge you to use your leadership […] to call for a moratorium on the U.S. Department of Defense's 1033 program — the largest and most prominent federal program providing police departments with military equipment — until Congress holds hearings to provide the public with important assurances and to consider various legislative proposals about this issue."

Some of the signees of the letter include the American Civil Liberties Union, FreedomWorks, the National Association for the Advancement of Colored People, and the Sunlight Foundation.

The groups wrote that "unfettered access to military equipment" for police departments "threatens fundamental constitutional rights, undermines public trust in our government, and is an enormous waste of taxpayer dollars."

"[S]uch federal programs — to the extent they provide military equipment or facilitate its acquisition — must be subject to necessary limits and additional oversight due to their corrosive impact on constitutional and community policing and exacerbation of racial tension in this country," the letter said. It asked for a suspension of the program until Congress holds hearings to prove "what steps the federal government is taking to provide oversight and accountability."

The Trump administration rolled back restrictions on the so-called militarization of police program that Sessions said "went too far" and that the loosening of them would go into effect immediately.

According to the Defense Logistics Agency Disposition Services, equipment worth nearly $460 million was transferred to state and local police in 2013 alone.