CHICAGO (CBS) — More than 400 guns are off the streets of Chicago, all thanks to a gun turn-in event by the city’s police department.

It took officers just four hours to collect the weapons on Saturday at New Life Covenant Church in the Grand Crossing neighborhood.

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People received a $100 gift card for every gun they turned in.

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B.B. guns, air guns and replicas were exchanged for $10 gift cards.

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Chicago police say the turn-in event yielded a higher number of guns than usual.