Householders are being urged to carry out security checks after several garage break-ins.
There have been four reports of crooks forcing their way into garages in Hemel Hempstead’s Wharfdale, Westerdale, Great Hart and Mendip Way.
In three of the break-ins mountain bikes were stolen.
PC Michael Ball said: “We are asking people to be vigilant and look out for people acting suspiciously in gardens or around garages.
“It is also advisable to register your bike and other valuables, such as mobile phones, for free on www.immobilise.com, so if your property is ever stolen and subsequently recovered by police, we can return the item to you. It only takes a few minutes to register.”
People are also urged to ensure garages, sheds and garden gates are secure and that fences are in good condition.