One girl was treated for a facial injury received after she was punched, Phenicie said. One of the club's 10 bouncers was also injured and taken to the hospital, he said.
"That's the worst we've had out there for awhile," Phenicie said.
One of the club's bouncers told police that the driver of a car he was chasing on foot down Myrtle Avenue pointed a gun at him, Phenicie said.
The driver, who was involved in one of the fights, hit the sign out front with his car as he was leaving, according to Extremes owner Mark Hoffman.
The bouncer and an off-duty Waynesboro police officer both reported they heard gunshots in the area of East Second Street and Myrtle Avenue, but police couldn't find any shell casings, Phenicie said.
Hoffman said there were up to five teens in the silver-colored Lincoln Town Car, with Maryland tags, all believed to be from Hagerstown.
A Chambersburg man, Darryl Coble, 18, of 331 S. Hackberry Drive, was charged with disorderly conduct and released.
When the fights broke out, club bouncers were forced to spray pepper mace on the offenders, Hoffman said.
But the irritant got into the air conditioning ducts and spread mace among the crowd, according to Phenicie and Hoffman.
Employees got everyone to the club's upper level but Hoffman said he had no choice but to "shut down and get everyone out."
"When police got here we had things pretty much under control," Hoffman said.
According to the police report, several young males were running from the front door of the club and one of the bouncers was on his hands and knees in front of the Sunoco gas station next door.
It was determined later that the bouncer had tripped and fallen while he was chasing one of the fight suspects, Phenicie said.
Once the crowd was outside, police separated them into smaller groups, Phenicie said. Police stayed at the club until the teens got rides home, Phenicie said.
Though Saturday's incident was the first police have had to deal with at the club in about two months, Phenicie reiterated that he doesn't have the manpower to control a large volume of teens when they get out of control.
"We don't have enough people to take care of this," he said, adding that Greencastle police had to be called to handle a hit-and-run accident in Waynesboro because the borough's officers were at Extremes.
Hoffman said he's unhappy with the police department's response, claiming that three officers ignored the trouble inside the club when they first got there.
"Why did the cops only arrest one person?" he asked. "We have a right to expect backup. We didn't get it. They stood and watched us."
Hoffman said that lack of police protection gives the teens the impression that they'll get away with causing trouble.