Authorities are looking for a man who may have information about a homemade explosive that someone set off near the Colorado Springs chapter of the NAACP.

The blast happened Tuesday outside a barber shop that's next door to the group's office, which is about an hour south of Denver. There were no injuries and only minor damage, police said.

An improvised explosive device was detonated against the building, but it was too soon to know whether the nation's oldest civil rights organization was the target, FBI spokeswoman Amy Sanders said. The agency sent members of its Joint Terrorism Task Force to help investigate.

Sanders said investigators were looking for a balding white man in his 40s who may be driving a dirty pickup truck. It could have an open tailgate or a missing or covered license plate.

Investigators Tuesday were examining a red gasoline canister with a yellow nozzle that had been placed next to the explosive device but did not ignite. They also checked pieces of duct tape and metal lying 40 to 50 feet away from the explosion site.

Residents living nearby said they heard a single, loud "boom" but saw no fire. One neighbor, Gregory Alan Johnson, said he was unaware of prior problems near the NAACP's office. The organization shares the building with the barber shop, whose customers are predominantly black.

Chapter President Henry Allen Jr. told The Colorado Springs Gazette the blast was strong enough to knock items off the walls. He said he was hesitant to call the explosion a hate crime without more information but said the organization will move on.

"This won't deter us from doing the job we want to do in the community," Allen said.

The organization's national office issued a statement saying it was looking forward to a full and thorough investigation.