Police have launched a crackdown on crime in rural parts of south-west Hertfordshire after a spate of burglaries at local farms.

Officers from Hertfordshire Police are visiting more than 80 farms to provide crime prevention advice as part of Operation Thornbill, which was launched last month.

Residents can also label their valuable items with a state-of-the-art liquid called Enigma Tag, which contains a unique bar code so any stolen goods can be traced back to their owners.

On Monday, the Watford Observer joined PC Paul Knowles and Sergeant Ryan Hemmings as they visited farms in Sarratt, Chandlers Cross and Chorleywood to hand out advice and information to landowners.

Farm machinery, horse boxes and trailers, saddles, chainsaws and tools were among the items all tagged with the liquid, which comes in pots shaped like nail varnish and contains enough to label up to 70 items.

The tag can then be seen under ultra-violet light and scanned by a microscope to reveal its unique code in order to trace the item's owner.

PC Knowles, the rural liaison officer for the Rickmansworth Safer Neighbourhoods team, said: “It's a deterrent for the people who are thinking of stealing them and a deterrent for people who are thinking of buying them.

“You get a few opportunist crimes where they take trailers or tractors, but they definitely know what's worth taking and what's not.”

Among the farms visited on Monday was one owned by Glynn and Susan Humphreys, in Redhall Lane.

Susan, who revealed they had been the targets of burglars in recent years, said: “It all goes as a deterrent. That's all you can do.

“We have been burgled a couple of times in the house and a couple of times outside. It's just annoying more than anything.”

Operation Thornbill began in October following 16 burglaries in the Sarratt area since June.

Speaking of the Enigma Tag, Sgt Hemmings said: “It's very new. Only time will tell if it works. The results will be shown if we do have a burglary and we find the items at a horse fair.

“If that happens - and hopefully it won't - we will see it as a positive.

“It's a preventative measure but if unfortunately a burglary happens and we uncover some of the saddles, that will be proof that this initiative will be doing a really good job.”