Montgomery County police said they responded to the 13800 block of Outlet Dr., near Columbia Pike and Briggs Chaney Road, around 5:20 p.m.
Witnesses told FOX 5 that some young men started arguing outside That Was Easy Barbershop.
A woman who was inside at the time said someone yelled for everyone to get on the ground and then the shooting started.
The door of the shop was shattered and the woman, who didn’t want to be identified, was among those whose vehicle was hit by bullets.
At least five cars appeared to be damaged and there were multiple shell casings visible in the parking lot.
Police said one man was shot in the upper body and remained hospitalized in serious condition as of Sunday night.
Police said they were looking for more than one suspect and no arrests had been made.
Christopher Bolton said he came to the scene as soon as he heard about the shooting because he often goes to the barbershop and knows the employees well.
"It happens all around the country and now it’s come here," Bolton said. "If you have a dispute, talk it out. Leave the guns at home. Stop shooting people. Parents, tell your kids this is not OK. Grown-ups, shooting people is not OK. Resolve it with words. We got to stop the shooting, we got to."