Up to 600 letters have been stolen by thieves in Worcestershire who broke into a postman's car and stole two mail bags.
The incident happened in Three Oaks Road, Wythall, at about 0730 on Wednesday.
When the postman, who had been delivering mail, returned to his green Fiat Bravo he found a window smashed and the boot of the car open.
The missing letters were meant for delivery in the area.
Police have appealed for anyone who saw anything suspicious in the area at the time of the break-in, or who knows the whereabouts of the bags to contact them.
A spokesman for Royal Mail confirmed in some circumstances postmen and women use cars instead of liveried vans.