A gunman involved in a spate of mobile phone robberies in a Bradford park has been locked up.

Kevin Johnson, 22, was arrested in August after police launched a manhunt following a series of incidents in Bowling Park.

The city's crown court heard that during one robbery Johnson pointed a gas-powered pellet gun at the chest of a 15-year-old boy and then aimed the imitation weapon at the head of his 15-year-old friend.

Prosecutor Lesley Dickinson said the next day Johnson and his 20-year-old accomplice Michael Burke approached another group of three youngsters in the park and this time told a 13-year-old girl: "Don't make me use this" as he brandished the handgun.

Terrified victims handed over four mobiles phones worth more than £400 during those two robberies and the duo also admitted stealing another mobile phone from a 17-year-old boy in the park.

Yesterday, Judge Robert Bartfield used new powers to pass a so-called "imprisonment for public protection" sentence on Johnson after he concluded that he posed a significant risk of serious harm to the public.

Judge Bartfield said he was satisfied Johnson had the idea for carrying out the robberies and had asked Burke to bring his imitation gun.

"You are the more intelligent of the two and in... present a worrying picture," the judge told Johnson.

He described him as "a manipulative and deceptive" man who had not faced up to what he had done.

Johnson, of Summerlands Grove, West Bowling, Bradford, will have to serve at least two years and 10 months behind bars.

Johnson, who had previous convictions for assault, theft and criminal damage, pleaded guilty last month to two charges of possessing an imitation firearm with intent to commit an offence, four charges of robbery and one of theft.

Burke, of Salcombe Place, Holme Wood, Bradford, also admitted the four robbery offences and one of theft.

Judge Bartfield sentenced him to a term of four-and-a-half years in a young offenders' institution.

Burke's barrister John Harrison said: "He is deeply ashamed of his participation in these offences.

Nicholas Askins, for Johnson, said his client had been frank with the police and had now admitted involvement in another incident of attempted robbery which had been taken into consideration.