WATERVILLE – Police officers arrived at the restaurant on Main Street and pointed their flashlights into the darkness, illuminating scores of people scuffling with each other on the floor, hurling themselves over booths and scrambling for the door.

“It was pretty much chaos — a very chaotic mass of people,” Waterville Police Sgt. Daniel Ames said.

That was at about 1:20 a.m. Sunday at the Waterville House of Pizza, at 139 Main St., where nine officers arrived to disperse an unruly crowd.

Ames estimated at least 50 to 75 people were crammed in the restaurant when police arrived, and “the majority of them were intoxicated” after spending an evening at local bars. Five people were arrested after they either refused to stop fighting or struggled with police, Ames said.

No one was injured seriously enough to require treatment at a hospital, Ames said.

“The whole place was like a nightmare,” Waterville House of Pizza owner Steve Kosmidis said Sunday morning.

Arrested and charged were Frank A. Curtis, 32, of 22 Boothby St., Waterville, disorderly conduct and resisting arrest; Tasha S. Pelletier, 26, of 14 Powell Ave., Oakland, obstructing government administration; Taylor L. Poulin, 22, of 18 Crestwood Drive, Waterville, disorderly conduct; John M. Sheehan Jr., 28, of 14 Crestwood Drive, Waterville, disorderly conduct and resisting arrest; and Toni M. Rodriguez, 28, of 17 Crawford St., Waterville, disorderly conduct.

All were released by police on unsecured bail and are scheduled to appear in Waterville District Court on Nov. 16, except Sheehan, whose court date is Dec. 7.

Kosmidis said his restaurant was not damaged during the melee, but it was the worst problem he’s had. The restaurant is open until 2 a.m., long after most area eateries have closed on weekends.

Kosmidis said he doesn’t know why the fighting started; people just began yelling and screaming, and before long several fights had broken out as he and other employees were busy taking orders.

Kosmidis said he tried to break up one fight but gave up and called police and switched off the lights inside.

Flabbergasted, he watched as two women pulled each other’s hair and continued fighting out on Main Street. One of those women left her shoes behind, he said.

In addition to Waterville police, officers also arrived from Fairfield, Winslow and the Kennebec County Sheriff’s Office. Officers began wading through the crowd in the darkness, attempting to break up the fighting, Ames said.

One of those arrested, Sheehan, was shocked with a Taser stun gun because he wouldn’t obey police commands to stop fighting, Ames said.

Ames said many people at the House of Pizza were wearing T-shirts reading “Get Naked,” a loose-knit group organized through the social networking site Facebook that meets on occasional weekend nights for “pub crawls.”

Ames said police have had encounters with people on the pub crawls before. But while police have responded to fights or mischief at the Waterville House of Pizza on previous nights, the latest skirmish was the most problematic yet, he said.

Kosmidis said he’s not sure what he could do to dissuade mischief at his restaurant and doesn’t want to shorten his late-night hours because “we do good business at night.” But other cases of drunken customers have resulted in a smashed mirror and vandalism in the bathrooms, he said.

“I think we have to do something,” Kosmidis said. “They bring it from the bars.”