text: Police said three 15-year-olds, two 16-year-olds and one 17-year-old struck 14 times in less than a month, threatening Birmingham motorists with knives and a firearm.
  They have been given sentences of between five years and six months at youth offenders institutions.
  All six pleaded guilty to conspiracy to rob.
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  At Birmingham Crown Court, one of the 15-year-olds, from Great Barr, was given five years after admitting conspiracy to rob, conspiracy to possess an imitation firearm with intent to commit an indictable offence and dangerous driving.
  A second 15-year-old, from Bordesley Green, was given three years, while a 16-year-old, from Shard End, was sentenced to two years.
  The 17-year-old, from Quinton, and the second 16-year-old, from Woodgate Valley, were given eight months. The third 15-year-old, from Winson Green, was given six months.
  Several motorists were physically assaulted and a moped rider was hit with a hammer as he tried to run away, West Midlands Police said.
  It said they struck three times on the evening of 7 September, stealing a VW Polo at knifepoint in Winson Green and taking mopeds from two bikers in Kingstanding and Handsworth.
  Examination of phones seized from the teen robbers revealed chat groups used to plan and boast about offences, suggestions on where to hide evidence and what to steal, West Midlands Police said.
  Det Con Sam Price said: "These were very nasty offences and really quite shocking given their ages.
  "Looking at the message exchanges they seemed to revel in the thrill of committing offences and almost deemed it as some kind of sick game."
target: A teenage gang which carried out violent car-jackings used chat groups to plan and boast about offences.