MELVILLE, N.Y. — The prospect of frozen paintballs being used to damage property on Halloween, part of a violent trend in vandalism linked to the trick-or-treat night, has cops and communities on alert, police in Suffolk County say.

Last year on Halloween, about 25 houses in the county were damaged by people wielding paintball guns, according to Karina Singh, vice president of Keep the Peace Foundation, a community organization in Amityville. And Nassau County police arrested five teens for paintball use around Halloween last year, with charges ranging from criminal mischief to possession of a dangerous weapon, said Officer Adele Burke.

This year, the danger is heightened by kids freezing the small balls, making them extremely hazardous, police said.

“Frozen paintballs are an irresponsible and dangerous thing,” said Anthony Pennino of Huntington, who owns Island Paintball Supplies with his son, Anthony. “They could easily break a window, or worse, take out an eye.”

Freezing a paintball makes it about as hard as a marble, said Island Paintball Supplies technician Vinny Mortarotti. Fired from a gun at 200 mph, the .68-caliber paintballs are capable of damaging eyes, causing blood welts and even killing someone.

Island Paintball, along with High Velocity Paintball of Coram, stops selling paint and refilling the guns’ carbon-dioxide cylinders several weeks before Halloween.

“A few years ago, I noticed our paint sales were up around Halloween, around the same time vandalism became popular,” the elder Pennino said. “So whenever Halloween comes around, we know it’s time to start using our judgment when it comes to selling paintballs.”