Police in New Westminster are warning car owners to be vigilant after a spate of thefts in the B.C. city.

The thieves are targeting catalytic converters — the emissions-control device attached to a vehicle's exhaust system — which, police say, can be sold for small amounts to scrap metal dealers.

The spike in thefts has centred on newer model Volkswagen sedans in the streets around McBride Boulevard and have taken place overnight.

"These offences are often under-reported because owners generally take their vehicles in for repair. We want to encourage anyone who has had their catalytic converter stolen to report it to us," acting Sgt. Jeff Scott said in a statement.

Police are also recommending owners park their vehicles in secured areas or make sure their street spot is well lit and in higher traffic.

They also suggest drivers look into low-cost alarm systems.