The motivation behind an explosion outside the building that houses the Colorado Springs office of the NAACP has not been determined and multiple possibilities are being explored, the Federal Bureau of Investigation said Wednesday.

"It is certainly a possibility of being a hate crime or domestic terrorism, however we are exploring all possibilities of potential motive," said Amy Sanders, spokeswoman for the FBI in Denver.

Jeff Dorschner, a spokesman for the U.S. Attorney's Office in Colorado, said an assistant U.S. attorney with expertise in "both terrorism-related matters and matters related to destructive devices" is supporting the investigation and working with the FBI. The agency reported the incident to the Department of Justice, he said, and is providing details and updates regarding the investigation.

An improvised explosive device went off and knocked items off walls in the NAACP office around 10:45 a.m. Tuesday. Police initially reported that an explosion had been heard outside Mr. G's Hair Design Studios, a barbershop that occupies the same building at 603 S. El Paso St. The device was near the northeast corner of the building, adjacent to a wall of the barbershop.

No one was injured and the building was not damaged beyond some charring on the outside wall of the barbershop.

Gene Southerland, owner of Mr. G's, said police told him the blast was caused by a flare and some type of pipe bomb next to a gas can, which did not ignite.

Authorities would not confirm details of the items found at the scene.

Sanders was unable to say what kind of damage could have been caused had the gas can exploded, and could not say how much gas was in the container. "Based on investigations to date, it does not appear it was detonated accidentally," Sanders said.

Investigators may be looking at the possibility of intended arson rather than an explosion, she said.

Sanders said she would not be able to release whether anyone connected to the building was being protected by law enforcement. She also would not say whether any surveillance cameras were in the area and may have caught the person of interest - a white, balding male in his 40s with a white, dirty truck - on video, citing the ongoing investigation.

The NAACP office was closed Wednesday morning - no volunteers or staff members in sight. Southerland said the office doesn't usually keep regular hours because it is staffed mostly by volunteers. Rosemary Harris Lytle, president of the Colorado/Montana/Wyoming NAACP State Conference, said the office was closed Wednesday based on what happened Tuesday and because of bad weather conditions.

Southerland was working when the explosion happened, and he said it was "so loud, for a minute I didn't know if it happened inside or outside."

A few containers fell off a shelf, but the barbershop was otherwise unharmed. He went outside and saw a gas can and what looked like a chunk of dynamite. He said he picked up the large gas can, possibly 5-gallon sized, and said it felt full. Police later told him the device was a pipe bomb and flare rigged to ignite the gas can, he said.

In addition to possible motives involving the NAACP, the FBI is investigating whether the barbershop could have been targeted.

Lt. Catherine Buckley, a spokeswoman for the Colorado Springs Police Department, wrote in an email "preliminarily there is nothing which has been identified as concerning in any previous calls for service" at the location.

Southerland said he didn't think he was a target, and that it's no coincidence the explosion happened near the NAACP office. The national organization has been vocal about the Ferguson, Mo., fatal police shooting of 18-year-old Michael Brown, and has been calling for change in light of grand juries that have not held officers responsible for killing unarmed black men.

"Personally, I think that it's all related," Southerland said. "What's happening in Ferguson, what's happening here, it's all related."

On Twitter, the #NAACPBombing hashtag was trending worldwide Wednesday morning, with some people criticizing what they believe was a lack of coverage by local and national media. News of the explosion was reported by media organizations such as The Associated Press, CNN and the Los Angeles Times. The story was also picked up by outlets around the world, including the London-based Guardian newspaper.

A tweet from Georgia congressman and civil rights leader John Lewis on Wednesday said: "I am deeply troubled by the bombing in Colorado. It reminds me of another period. These stories cannot be swept under the rug #NAACPBombing."

Southerland said he thought the national attention was "outstanding," and he was glad the incident has made people stop and think.

He said he was grateful for how quickly Colorado Springs police, bomb squads and the FBI responded.

One woman who lives down the street from the building said Wednesday she initially thought a house might have blown up. She had hoped it was just some teenagers messing around, but she realized it was serious when the FBI knocked on her door.

She didn't see the man authorities are after, but said that her neighbor's dog was barking excessively in the direction of the NAACP office prior to the explosion..


Gazette reporter Stephen Hobbs contributed to this report.