MADISON, Wis. (AP) -- Prosecutors have charged a state Capitol worker with using a knife to pop a protester's balloon.

State Department of Administration Assistant Director of Facilities Ron Blair faces a misdemeanor count of disorderly conduct with a dangerous weapon. Dane County Court Commissioner Ann Sayles on Thursday entered a not guilty plea for Blair and approved a signature bond with the condition he not use knives on the job.

According to a criminal complaint, Blair came up behind a protester in the Capitol on July 25 and used a knife on his multi-tool device to pop her balloon. He told police he just snapped.

Protesters angry over Gov. Scott Walker's divisive collective bargaining law have been gathering in the Capitol for a thundering sing-along every noon hour for months.