Rep. John Lewis (D-Ga.), a leader during the civil rights movement, said he was "deeply troubled" by the Tuesday detonation of an explosive device outside of a building in Colorado that houses a local chapter of the National Association for the Advancement of Colored People (NAACP).
"It reminds me of another period. These stories cannot be swept under the rug," he said in a tweet.
The building that houses the chapter's offices also includes a hair salon, but the owner told the Denver Post that he did not believe he had been the target.
The bomb did not do great damage the building or injure anyone, but the Post reported that the resulting noise was heard throughout the neighborhood and that items were knocked off of walls inside the building.
Authorities said on Tuesday they are looking for a balding white man in his 40s who may have information about the bombing.
"The NAACP looks forward to a full and thorough investigation into this matter by federal agents and local law enforcement," the group said in a statement.
Social media attention propelled the news of the bombing into national headlines on Wednesday. It comes amidst national protests over the way the criminal justice system treats minorities — particularly black Americans.