Two men have been robbed of their top-of-the-range games consoles minutes after buying them.

The pair, aged 25 and 27, were among the first to get their hands on the brand new Microsoft Xbox One in Gloucester when it went on sale at midnight on Friday.

Gloucestershire police said the men had returned to their car in St Michael's Square car park at about 12.15am when they were robbed. They were loading the £430 consoles into the vehicle when they were assaulted. The 25-year-old suffered injuries to his face and the 27-year-old was knocked unconscious.

Police are warning shoppers to be extra vigilant if they have just bought the Xbox One or the Sony PS4, which will be released in the UK next week.

A force spokeswoman said: "Inquiries are ongoing to find those responsible and officers are eager to hear from anyone else that was in the area and may have witnessed the robbery.

"With demand still high for the Xbox One and the new Sony PS4 release next week, Gloucestershire police are urging anyone planning to make a late-night trip to purchase one of the items to consider carrying the item in another bag, other than the one supplied by the shop, so it is not obvious as to what the bag contains.

"Police also suggest that you park your car in a well-lit area, and as near to the shop as possible to keep your journey short.

"If you become suspicious of anyone around you then call the police.

"Gloucestershire police's crime prevention advisers will also be getting in touch with shops opening late to sell the items to offer advice."

Christened "Xbone" by some gamers, the Xbox One is the successor to 2005's long-lasting Xbox 360 and the third device in the Xbox family after Microsoft entered the console market in 2001.

It has a 500GB hard drive, an eight-core processor and a beefed-up version of Microsoft's Kinect system, which allows a camera to track and interpret human body movements.