Police are urging children to leave expensive gadgets at home after a violent robbery landed a 12-year-old boy in hospital.

The boy was robbed of his PlayStation Portable (PSP) games console on Friday at about 4pm, as he was leaving school in Hendon.

The games machine was one of this year's best-selling Christmas presents, but the £200 device is proving attractive to muggers.

Police revealed earlier this year that two-thirds of all street robberies involve the theft of expensive electronic equipment, and officers now fear that the PSP will follow the iPod as the target of choice.

The attack happened in Downage, when a group of teenagers approached the boy near his school gates.

He was thrown to the ground, injuring his hand, while his PSP and mobile phone were stolen. The boy was taken to Barnet Hospital, suffering concussion, cuts and bruising, and remained there over the weekend.

There have been two violent thefts involving PSP machines since they came onto the market at Christmas.

Acting Detective Chief Inspector Murray Duffin, of Barnet police, said: "Sadly, small portable items of technology are just too much of a temptation to some of the criminal fraternity and things like PSPs and iPods that are not used in school should maybe be left safely at home or kept well out of sight when in the street.

"The amount of violence used in this attack was unnecessary and gratuitous and we would hope that anyone with any information about this incident will contact us quickly."

One robber was described as Asian, aged about 18, and was wearing a green camouflage, hooded jacket. A second was a dark skinned European man, also aged about 18, and wearing a navy blue hooded top. If you have any information, call police on 020 8733 4595.