A low explosive device was detonated Friday morning at the Prosecutor General's Office in Valle Del Cauca, southwest Colombia, destroying the building's doors and windows, EFE reported.
The bomb squad entered the building after hearing reports of a possible second bomb, but no device was found.
Authorities have not confirmed the exact number of people who were affected by the blast but say no one was fatally wounded.
Reports indicate at least five people were treated for injuries.
Police have no suspects, but Colombia's Revolutionary Armed Forces, or FARC, along with several other criminal gangs allegedly have a presence in the area.