Bournemouth Beach Daylight Robbery

Yesterday Sergey, Jakiv and I were walking along Bournemouth beach. We sat on a bench talking. Jakiv and Sergey decided to go swimming, leaving me with the clothes and bags.
I walked a few yards forward to take a photo but when I came back to the bench I found that my bag had been stolen. I think it was two teenagers quickly riding past on bicycles.
My bag was a computer bag and they must have thought that it was a laptop. Not a bag full of Russian dictionaries, a mobile phone and SIM card and all my personal photos.
They have gained nothing and I have lost a lot...I can't ring my wife anymore.
VICTOR