Worrying new figures show that 692 city homes were burgled in the first five months of this year – the equivalent of nine break-ins every two days and a 45 per cent increase on the same period in 2008.

Senior officers admit the increase is "a concern" and have launched a three-month crackdown, codenamed Operation Alert, aimed at driving the figures down.

Part of the operation will include an unusual tactic – 60 known burglars are to get hand-delivered letters warning them to go straight or face the full weight of the law.

The initiative will be backed up with action as officers keep the 60 under close surveillance – putting the worst offenders under intense pressure by visiting them in their homes up to three times a week.

The letter, seen by The Evening Telegraph, warns: "We have identified you as being among a group of people suspected of being involved in burglaries in Peterborough.

"I would like to stress how seriously we take this type of crime, and I can assure you that over the coming weeks we will be fighting it on a number of fronts, including regular visits to you and others across the city.

"Therefore, if you are currently involved in burglary, our message is simple: either stop, or we will use the full range of powers at our disposal to catch and convict you."

Operation Alert is the brainchild of Detective Inspector Neil Sloan, who heads up Peterborough's priority crime team.

He said house burglaries had increased right across the city with no particular areas being hotspots. He said there was no single cause for the hike, but the recession was likely to be a factor, plus individuals' need to fund various addictions.

"It is very concerning," he said. "Burglary is a horrible crime which often leaves victims highly distressed and traumatised.

"Our response is to launch Operation Alert, which includes a real focus on those people who have convictions for burglary and those who we suspect of being involved in burglary through intelligence.

"If they choose not to stop committing crimes, we will do everything possible to catch and convict them, and I'm very confident this operation will have a positive effect."

The letters tactic is being launched because police do not have enough evidence to link particular individuals to unsolved crimes.

Of the 60 people identified, a top 10 "most wanted" will be given the closest attention.