Caveat: I am not an Ohio lawyer! Take the following at your own peril.
I ran a search for "firearms" at:
http://codes.ohio.gov/orc
Here's what I found:
3761.16 Areas threatened by riot may be cordoned off.
The chief administrative officer of a political subdivision with police powers, when engaged in suppressing a riot or when there is a clear and present danger of a riot, may cordon off any area or areas threatened by the riot and prohibit persons from entering the cordoned off area or areas except when carrying on necessary and legitimate pursuits and may prohibit the sale, offering for sale, dispensing, or transportation of firearms or other dangerous weapons, ammunition, dynamite, or other dangerous explosives in, to, or from the cordoned off areas.
Effective Date: 07-01-1996
I'm afraid that I don't have time today to continue digging.