Police have urged people to take simple steps to protect their mobile phones from thieves after Leicester was named as a theft hotspot.
Insurance firm LV said 742 phones were stolen in the city's Castle ward, which includes the city centre and Clarendon Park, between April and the end of August.
It said the city centre was one of the areas with a high incidence of thefts and robberies. Others included Sheffield, Bristol and parts of London.
The firm also said children as young as nine had been caught stealing phones in the city in the past three years.
In Leicestershire as a whole between April 2009 and March 2010, the force recorded 3,887 thefts or robberies involving mobile phones.
This rose to 4,135 in the following 12 months.
So far, between April this year and the end of August, 2,656 handsets have been stolen. Police said the majority of thefts took place in the city centre's pubs and nightclubs, with phones and other valuables left unattended on tables or in bags or coats.
Inspector Chris Cockerill, commander of city centre police, said: "We've done a huge amount of crime prevention work in the pubs and clubs at night and in the city centre during the day.
"We've had good arrests and as a result thefts are falling.
"The majority of these incidents are thefts from unattended bags or coats.
"We've also had cases of people leaving them on top of parking meters, walking away and returning to find that they are gone.
"Robberies, where a phone is taken with force or the threat of force, are rare."
According to LV, thefts have risen year-on-year since 2010.
In the first eight months of this year, 264 mobile phone thefts were reported nationally each day – an increase of 7 per cent compared with 2011 figures.
The firm said it believed stolen mobiles were usually sold to unsuspecting buyers through online auction sites or exported for sale in Africa, Asia and Europe.
John O'Roarke, managing director of LV home insurance, said: "We have seen a real shift in theft claims over the past decade, with thieves preferring to target small, easily portable items such as mobile phones and gadgets.
"The latest smartphones are worth hundreds of pounds on the black market and can be easily sold on, making them particularly attractive to opportunistic thieves.
"The best way to protect yourself from theft is to use a password on your phone, keep it hidden away when you're not using it and ensure your phone is properly insured."
