Cheryl Cole 'increases signing security'

Cheryl Cole has reportedly increased her personal security ahead of an upcoming book signing.

According to Metro, the X Factor judge has taken extra precautions before launching her Through My Eyes memoir this week.

Cole is said to be worried after she reportedly lost a ring when being grabbed by a fan in June. Leona Lewis's assault by a fan at a book signing last year is also believed to have concerned Cole.

"Everyone's a bit nervous about what happened to Leona," a source told the newspaper. "Cheryl's security team has been beefed up and no-one is taking any chances this time."

In her book, Cole has described friend Derek Hough as a sweetheart and frequent collaborator will.i.am as "a very special person". It has been claimed that she does not mention her ex-husband Ashley in the account of her last 12 months.