Burglars stole power tools and surveying equipment from a building site in Sheffield.
They struck at a site in Suffolk Road in the city centre between 2pm on Saturday, April 23 and 7am on Monday, April 25.
A South Yorkshire Police spokesman said: “Persons unknown are understood to have broken into site offices at a building development in Suffolk Road, Sheffield.
“Significant damage was caused and a number of expensive electrical items were taken, including surveying equipment.
“Laptop computers, power tools, hand tools and a quantity of mains cable were also taken during the incident.
“Officers are keen to hear from anyone that may have witnessed suspicious activity at the site over the weekend, or if anyone has been offered any of the items for sale.”
Call South Yorkshire Police on 101.