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.

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

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

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