Road signs are being cut down or driven into, across Canterbury's Waimakariri District

There's been a sharp increase in road sign vandalism in the Mandeville and Ohoka areas.

It comes after a recent change in speed limits across the district.

Deputy Mayor Neville Atkinson says this isn't a victimless crime.

He says people can be put at extreme risk if there are no signs and they don't know the area.