LEWISTON — Police are investigating a rash of car burglaries which investigators say are mostly crimes of opportunity.

Over the past week, someone has been prowling streets and driveways in the area around outer College Street, searching for unlocked vehicles with loot inside.

“They’re grabbing anything of value they can find,” police Lt. Michael McGonagle said.

Exact numbers were not available on Wednesday but police estimate at least a dozen cars, trucks and minivans have been targeted. Their advice is simple: Avoid leaving valuables inside your vehicle and keep it locked at all times.

Police were also asking for help from the public.

“If you see somebody who looks suspicious — somebody walking up driveways or along the street and checking cars, call us,” McGonagle said.

The burglaries have been committed at all hours of the day, police said, not just overnight.