A robber got away with hundreds of mobile phones after hijacking a van.
A man smashed the driver's window as the van approached Northampton's Riverside Industrial Estate, opened the door and threatened to stab the driver.
The attacker drove off in the white Mercedes van after forcing the driver out of the passenger door.
The van was abandoned on the Bedford Road, near to Barns Meadow roundabout on Friday minus the consignment of 500 Samsung D500 mobile phones.
'Very strong'
The offender is described as a a very strong white man, possibly between 30 and 40 years old with a medium build. He has light brown or sandy coloured hair and was possibly wearing a Parka-style jacket.
The phones were loaded into the van in High Wycombe, Buckinghamshire, and officers believe it may have been followed from there.