A Columbus Fire Department official says firefighters and police have not found any visual evidence of an explosion at the city's police headquarters.
Battalion Chief Patrick Ferguson says emergency responders are still at the scene in downtown Columbus. He says the cause of what a caller reported as an explosion at about 7:30 p.m. has not been determined. The building has since been evacuated and locked down.
No injuries have been reported. Ferguson says there are no signs of smoke.
A police public information officer did not immediately return a phone message.
The headquarters building is located a few blocks from the Ohio state house.
The police department's non-emergency and 911 lines were not affected.