U.S. President Barack Obama has ordered a review of the distribution of military hardware to state and local police out of concern at how such equipment has been used during racial unrest in Ferguson, Missouri.

A senior Obama administration official said on Saturday the president has ordered a review of federal programs and funding that enable state and local law enforcement to purchase military equipment.

Images of police wielding military-style guns and armor have alarmed many Americans following violence that was triggered by the fatal shooting of an African-American teenager, Michael Brown, by a white police officer in Ferguson.

Obama wants to know whether the programs, begun after the Sept. 11, 2001, attacks, are appropriate and whether state and local law enforcement are given proper training, the official said.

The review will be led by White House staff including the Domestic Policy Council, the National Security Council, the Office of Management and Budget, and relevant U.S. agencies including the Departments of Defense, Homeland Security, Justice and Treasury, and it will be carried out in coordination with Congress.

Obama signaled that he would review the programs on Monday at a White House news conference when he said he wanted to make sure police were purchasing equipment that they actually need because there is “a big difference between our military and our local law enforcement and we don’t want those lines blurred.”