Editor's note: This story has been updated to correct the location of the service member who was on site when the explosion occurred.

A Marine recruiter was in his office around the corner from an Air Force recruiting center in Oklahoma when it was bombed Monday.

Capt. Erin Ranaweera, a spokeswoman for the Air Force Recruiting Service, said Tuesday that the Marine was working late at the Marine recruiting office, located in the same strip mall as the Air Force center, when an explosive device exploded at about 10:45 p.m., local time. Ranaweera said the Marine felt the blast but was unharmed.

AFRS first said that a service member was inside the recruiting center when the explosion occurred, and later clarified that it was a Marine in his own recruiting station.

Ranaweera said the Air Force Recruiting Service is working with the Office of Special Investigations at Tinker Air Force Base in Oklahoma, as well as local agents from the FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives.

"We're very grateful that no one is harmed," Ranaweera said. "The office is closed now, but recruiters in the area are remaining vigilant and continue to remain dedicated to serving the folks in the area."

Ranaweera said that Air Force recruiters there are continuing to conduct their duties elsewhere.

Investigators have not ruled out domestic terrorism, Ranaweera said, but the motive remains unknown. A federal agent said Tuesday that the late-night blast could also have been a horrible prank.

Ranaweera said that officials are canvassing the area talking to officials from the various services — active duty, Guard and Reserve — to find out if they had received any threats recently.

Federal authorities said a device was set off around 10:30 p.m. Monday in front of the recruiting center. The center was closed at the time and no one was injured. Authorities declined to specify the nature of the device.

ATF spokeswoman Meredith Davis said agents are treating the matter as a domestic act of terror "out of an abundance of caution," because of the proximity to the recruiting center, but that it could also have been a prank or an accident.

"There's no doubt that military offices have been targeted in shootings and explosions in the past, but we also see people blowing off their fingers or blowing up their garages," Davis said. "And sometimes people see cops make a U-turn and they throw stuff, or see them coming and throw something."

The door of the center was blown off in the blast and landed in a parking space in front of the storefront and soot-covered windows. The office is situated in a commercial area that also houses small businesses, restaurants and financial planning firms. There is a movie theater nearby.

ATF and FBI agents are scouring the area for video surveillance that might have captured someone placing the device or could show a vehicle containing suspects, Davis said.

"It's a two-pronged investigation," she said. "There will be work being conducted on scene and being conducted in the field, such as interviews and recovery of (video) surveillance."

The Associated Press contributed to this report.