A Denver man denies that he attacked his supervisor at work.

Forty-one year old Ariel Calderon has pleaded not guilty to one count of aggravated assault and battery.

According to Mills Police, in February, Calderon and another co-worker got into a scuffle on the job and were separated by other workers.

Police say they were unable to determine what exactly happened and left the scene.

About an hour later, officers were called back for another incident, this time involving Calderon and a supervisor.

Calderon said he threw a hot air tool behind his back and struck the supervisor in the face, but the supervisor said that Calderon tried to stab him in the face out of anger, and started punching him.

Several other employees observed the assault and pulled Calderon off of the supervisor.

Calderon is free on $10,000 bond awaiting trail, and faces up to 10 years in prison if convicted.