Tills and cash have been stolen from five businesses during raids in Sheffield.
Thieves have struck in the neighbouring suburbs of Handsworth, Woodhouse, Holbrook and Beighton over the last few days.
South Yorkshire Police said raids have been reported in Bramley Park Road and Orgreave Close, both in Handsworth; Tilford Road, Woodhouse; Meadowbank Park, Holbrook and Rotherham Road, Beighton.
A police spokesman said: "The cash registers have been stolen at most of these break ins, along with other amounts of cash.
"Please be vigilant when you are out and about today and report any suspicious activity to 101 or 999 in an emergency.
"Thank you for your continued support, rest assured we are doing all we can to trace these offenders."