After a weekend which saw 34 bags and phones snatched in just two days, police have released images of suspects contributing to the epidemic.

Street robbery has been rising steadily in Islington – 33 per cent in the last year to almost 1,150 offences – and is now at such a crisis level, police have made it a priority. As well as the witness appeal, they have also launched an awareness campaign and undercover operations to catch the crooks in the act.

A typical snatch involves older teenagers riding past an iPhone user, grabbing the device and making off before the victim knows what is happening. Although most don’t use violence, there have been cases where victims have been brutally attacked.

Police are asking people to think twice before using their phones walking along the street – particularly in Upper Street and Essex Road, Islington, and Old Street and City Road, in Finsbury.

Det Insp Rita Tierney, in charge of Islington’s robbery squad, said: “We don’t want to scare people but we are seeing more than 25 snatches a week and people need to be more aware. It all happens so quickly and it is so easy for the robbers – you think it can’t happen to you but it can.

“Sometimes they get violent and use force to snatch the phone, or push the person away – even slap them round the face to shock them.

“It’s mainly iPhones, because they know they can sell them for �200, although it can be bags, other phones or cash cards. A group tried to steal a cash card in Upper Street the other night. The victim resisted and there ended up being a big fight.

‘‘The problem is we all walk down the street with our phones out, checking Facebook or emails. I know I used to. We want people to think about their surroundings and maybe check messages before you leave the bus or Tube station.”

Anyone with information can call 020 7421 0366 or email islingtonpolice@met.police.uk