Federal prosecutors are working to track down outside disruptors who they say infiltrated demonstrations in Atlanta and other cities over the weekend to corrupt and discredit what would have been peaceful protests of police killings.

“With the rioting that is occurring in many of our cities around the country, the voices of peaceful and legitimate protests have been hijacked by violent radical elements. Groups of outside radicals and agitators are exploiting the situation to pursue their own separate, violent, and extremist agenda,” U.S. Attorney General William P. Barr said Sunday in a written statement.