Yoko Ono has tweeted a provocative photo of John Lennon's bloodstained glasses.

The Beatles singer's widow has taken a stand in America's gun crime debate - which has been heightened following the Sandy Hook school shootings in December - by sharing a photo of the spectacles John was wearing on 8 Dec 1980 when he was shot dead by Mark Chapman.

She posted the image four times in a row yesterday (21.03.13) on the 44th anniversary of their wedding, accompanied by a different message for peace each time.

Yoko wrote: ''31,537 people are killed by guns in the USA every year. We are turning this beautiful country into war zone.''

She added: ''Over 1,057,000 people have been killed by guns in the USA since John Lennon was shot and killed on 8 Dec 1980.''

The philanthropic star continued: ''Together, let's bring back America, the green land of peace.''

''The death of a loved one is a hollowing experience. After 33 years our son Sean and I still miss him. Yoko Ono Lennon.''

The image - which shows Central Park in the background and featured on the cover of her 1981 album 'Season of Glass' - was retweeted over 8,000 times.