According to West Midlands Police, a number of vans have been broken into and work tools taken. A total of six vans have also been stolen.
The force has confirmed that eight reported van breaks have taken place on supermarket car parks.
A police spokesman said: “This is unusual. Please do not leave your vehicle unlocked or with the windows down.
“If you leave your van unlocked, it only takes a criminal a few seconds to search your vehicle and steal anything you have left inside, silently and without alerting you to the fact it is happening.”
The police has now issued guidance for those concerned to guard themselves against van crime.