However a spokesman for the Bureau of Alcohol, Tobacco and Explosives has confirmed the incident is being treated as a potential act of domestic terrorism.
Investigators have reportedly indicated such a designation can not occur until a suspect or a motive becomes known.
A United States Air Force recruiting office near Tulsa, Oklahoma was bombed on Monday evening.
The FBI said earlier Tuesday the explosion is not now being considered an act of terrorism.
The person of interest, identified Benjamin Rhoden, was taken into custody Tuesday afternoon at an apartment complex in south Tulsa, Fox 23 News reports.
"That government vehicle looks attractive setting outside that office in tulsa".
"It's a little bit comforting that they didn't want to kill anybody". "Obviously they would have done it in broad daylight if that were the case".
Nearby stores were open as usual on Tuesday.
On social media, he often complained about being mistreated by the air force and bemoaned the plight of other vets.
The extent of the damage is still unknown, but images from the aftermath show the blast twisted and opened the office's doors.
Several federal charges could be filed against the perpetrator, FBI Special Agent Jessi Rice told reporters. "So, we're treating it as strictly a criminal investigation with an explosive device", Rice said. She said investigators are using a two-pronged approach, sweeping both the crime scene and the surrounding area.