NEW YORK (WCBS 880) — With more than one serial groper still on the loose in Brooklyn, self-defense classes are popping up everywhere from Park Slope to Sunset Park.

Some classes are even being offered for free to help women learn what they can do to combat potential criminals.

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“When you’re in a situation, use whatever techniques you can whether it’s your voice, your body. You want to run and you want to get out of that situation as soon as possible before something bad happens,” Jodi Haywood, group fitness manager at Harbor Fitness in Park Slope, said.

LISTEN: Jodi Haywood describes lessons from self-defense class

Harbor Fitness is offering a free two-hour self-defense class on Sunday, and Haywood says there are many helpful techniques to fend off would-be attackers.

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“They do a really terrific exercise of using your voice, and they teach you basically how to maximize your power in your voice and learn how to scream and say no and find power in using your voice as well,” she said.

Haywood said the class will be both physical and mental, teaching how to be aware of your environment and following your instincts to avoid dicey situations. The class will take women through drills to learn how to break out of a situation and voice exercises.

One of the women who was attacked in Brooklyn screamed until the attacker let go and a bystander came to her aid.

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Haywood says the sooner a woman can get out of a bad situation the better, so whatever it takes to escape immediately is the right thing to do.