Hi-tech tracking devices and alarms are being fitted to cycles by police in a bid to halt the rising number of bikes being stolen in Oxford.

The city's dedicated cycle crime team, based at St Aldate's police station, is also being expanded from one to four officers in an effort to catch more bike thieves.

Alongside more conventional methods, the team will use "trap" bikes fitted with tracking devices, and covertly alarmed bikes to give officers an extra edge when conducting operations in cycle crime hotspots such as East Oxford.

Sgt Nick Garside, who heads the team, said: "The sheer number of cyclists and bikes within Oxford does give the criminals opportunities, and over the last year there has been a slight rise in the number of bikes being stolen.

"The expansion of the cycle crime team should demonstrate our commitment to deal with such crime, and where we can we use the technology and resources that are available to us to catch and prosecute those responsible."

The use of trap bikes was welcomed by James Styring, of Oxford cycling group Cyclox.

He said: "I think this is a fantastic idea and Cyclox fully support the police, because bike thefts are costing cyclists half a million pounds a year, and the number of claims means that insurance premiums are going up.

"These new measures could act as a serious deterrent for bike thieves."

In May last year, the first dedicated officer was appointed to coordinate and investigate cycle thefts.

The decision to expand the team one year on came as it emerged that Oxford is the fifth worst place in the country for bike thefts, with about 2,000 bikes stolen every year.

The new team will consist of a sergeant and three officers, supported by a number of analysts from the autocrime unit.

They will also be able to call upon other plain clothes officers to support them in specific operations and investigations.

Traditional hotspots for cycle crime in the city centre are around Magdalen Street and Broad Street.

But with the increase in CCTV, cycle thieves are becoming more wary and new areas are developing.

The Cowley Road and Iffley Road and the adjoining streets, known as the East Oxford triangle, are seeing an increase in the number of thefts, mainly from outside people's homes.

Nick Gilbert, crime reduction adviser based at Cowley police station, said: "While the new team concentrates on catching the cycle thieves we must all remember that many bicycle thefts are preventable.

"In addition to getting your bike insured, invest in a good quality lock, and if necessary, use two.

"They are not expensive, and when used to lock a bike to a fixed point will put off the most determined of thieves.

"It's not just the whole bike that thieves are looking for. As opportunists they will steal saddles, lights and wheels where they can, so if you have quick-release mechanisms use extra locks or take them with you.

"There are also ways of marking your bike so that if it does get stolen we can return it. By spending just a few pounds and taking a bit of time you can save yourself an expensive bill."