WELDON SPRING, Mo. (AP) — Police and federal authorities  are investigating after a piece of military ordnance was found following a standoff with a man threatening suicide in St. Charles County.

St. Charles County police were called around noon Thursday to a report of a suicidal person at a gas station in Weldon Spring. After a standoff, the man was taken into custody without incident.

The man’s vehicle was found near Highway 94. Police spokeswoman Val Joyner says officers found a piece of military ordnance, possibly a World War II bazooka round.

The St. Charles County bomb disposal unit removed the ordnance. Neighboring businesses were evacuated until the removal was completed Thursday afternoon.

The Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI bomb squad are assisting in the investigation.