Thieves smashed the windows of two vehicles in a car park in Lincoln popular with commuters.
It happened between 9pm on September 30 and 7am on October 1 at the Robin Hood car park just off Ruston Way.
It’s unclear what was taken from the cars at this stage.
Police are appealing for anyone in the area around the time who might have noticed anyone suspicious, either on foot or in a van.
Officers also advised people leaving their vehicles in car parks overnight to take all valuable items with them.
Anyone with information can call Lincolnshire Police on 101 quoting incident 411 of September 30.