One thousand pounds worth of diesel was siphoned from three lorries in Upwell.
The theft happened between 1.35am and 1.45am on May 14 at a lorry yard in Baptist Road.
Around 500-600 litres of diesel was siphoned from three HGV lorries.
In another incident in Outwell, three bikes were stolen from a garage off Wisbech Road, between 12.48pm on May 17 and 10am on May 19.
• Anyone with information on either incident is asked to call Norfolk Police on 101.