Officers investigating a cash-in-transit robbery in Hucknall are appealing for witnesses or anyone who has any information to come forward.
Two offenders wearing face coverings approached a security officer in the car park of the Tesco Extra store on Ashgate Road at around 9.40am on Thursday.
The suspects threatened him with a hammer, demanding cash.
They fled the scene in a stolen vehicle which was later found abandoned nearby.
The worker wasn't injured.
Detective Inspector Gayle Hart, of Nottinghamshire Police, said: "We are pursuing a number of lines of enquiry, including checking for any CCTV opportunities, and we’re urging anyone who saw anything suspicious or who has any information which could assist us with our enquiries to contact Nottinghamshire Police on 101, quoting incident number 206 of October 10."