Southfield police responded to a report of shots fired at AMC Star Southfield 20.
No injuries have been reported and at least one person was arrested according to reports.
According to Southfield police, two men were arguing, one reached for a gun and the second person pulled out a gun and shot.
Police are unsure if anyone was hit, a bullet casing was found inside the theater but no bullet or evidence of blood.
The man shot at fled, the suspect believed to have fired the gun was arrested and is cooperating with police.
One customer in the theater, "Kathy" told FOX 2 she saw multiple police officers running into the theater and said there may have been an incident in theater No. 18.
Kathy said that once she learned that there may have been a shooting from a concession worker, she fled the theater.
A message posted on the theater's website says the location is suffering a "Theatre Outage" and is temporarily closed.
A police spokesperson said units responded at the theater to the reported incident, but could provide no further information.
Stay with FOX 2 for more details as they become available.