Nearly 8,000 police officers are being used today in a "major crackdown" on thieves who target mobile phones and other valuables.

The Metropolitan Police said they had carried out dawn raids today on suspected thieves and those handling stolen goods, involving more than 7,500 officers across specialist teams.

London's police service also said high-visibility patrols would also take place in key areas, while the public would also see street briefings, weapon sweeps, knife arch operations and officers giving safety advice.

Officers will also be making spot checks and giving advice to pawn shops and other stores where thieves may try to sell on stolen goods.

The Met's Operation Ringtone comes as personal theft offences continue to rise in London by 14 per cent from June 2012 to May 2013 compared to the previous year, despite overall crime figures falling.

It was launched in February in five London boroughs: Lambeth, Westminster, Camden, Islington, and Hackney.

About 70 per cent of all theft person involves a mobile phone and the vast majority of those involve an Apple iPhone.

Around 7,000 phones are stolen every month in London.

Commander Stephen Watson, leading today's operation, said: “Crimes like burglary, robbery and theft have a huge impact on the people who are victims. 

"By targeting those people responsible, plus the networks they use to sell on stolen property or trade for drugs, we aim to make our streets a hostile place for them to operate.

He added: “We would also ask the public to take extra care of their valuables.

"Many of the thefts are taking place during the day in shops and cafes but at night the problem moves to bars and nightclubs."

If you are offered a phone you think may be stolen, or have any information about thieves and those profiting from stolen goods contact police on 101 or call Crimestoppers on 0800 555111.