AJAX, Ont. -- Police say they're investigating a series of thefts at banking machines in communities east of Toronto.

Durham regional police say the latest incident occurred last Friday afternoon when a 67-year-old man was forced to drive to an ATM in Ajax, Ont., and withdraw money for two suspects.

Investigators say the man had just parked his car when the suspects approached and forced him back into the vehicle.

The suspects made him drive to a nearby drive-through ATM and withdraw cash before driving off in his car.

Investigators say there have been four similar incidents in the past three weeks in Ajax and neighbouring Pickering, Ont.

They say it's not known if the incidents are connected.