Black Friday bargain-hunters caused chaos across Britain today as stores led by Asda slashed prices on Christmas electronics and gifts.
Frenzied shoppers caused a stampede in one shopping centre, while other Asda stores saw injuries, arrests and ugly squabbles over discount goods.
Asda opened some of its stores at 8am, leading desperate shoppers to snatch items off the shelves in seconds and fight among themselves.
A woman was taken to hospital with a suspected broken arm after a shopping centre stampede in Northern Ireland.
There were claims a heavily pregnant woman was pushed and shoved and pensioners were knocked to the ground by frantic shoppers at an Asda store in west Belfast.
Eyewitnesses outside one Asda store - where electronic tablets had been slashed to £49 - said there were queues from 5am.
Dozens of shoppers took to Twitter to describe the chaotic scenes which unfolded in Asda stores nationwide.
Other shoppers said bargain hunters descended 'like locusts' as soon as the doors opened, with the best bargains snatched off the shelves in under 10 minutes.
A spokesperson for North West Ambulance Services told Yahoo a woman was taken to hospital in Merseyside just before 9am after being 'assaulted' when she was pushed over the queue.
Meanwhile at an Asda in Bristol, police had to intervene following reports that a store security guard was assaulted.
A shopper visiting the supermarket to take advantage of an electronics mega-sale became involved in a bitter argument with staff at the store.
It is thought the trouble flared up when staff told him was only allowed to buy one of each product.
He was escorted from the store by security guards and was finally restrained by five members of staff - with one employee suffering a cut face.
An eyewitness said: 'He was being told by staff at Asda that he wasn't allowed to buy two TVs,
'Security then escorted him and he was arguing and filming them on his mobile phone when it was knocked out of his hand.
'He ended up being carted off handcuffed in a police but it was the security guards who got physical.'
Officers from Avon and Somerset Police arrived at the store in Cribbs Causeway, Bristol, and arrested a man.
There similarly chaotic scenes at Asda in Benton, North Tyneside, where some shelves were cleared in one minute as crazed shoppers overran the store.
Some of the biggest names on the high street slashed their prices on 'Black Friday', mirroring the US event which traditionally takes place on the first Friday after Thanksgiving.
It will be followed by 'Cyber Monday', where online retailers will also slash their prices as the Christmas shopping season gets into full swing.
Amazon is hoping to beat the 41 items it sold per second on Monday December 3 last year.
John Lewis said customers would be able to save up to 50% on selected small electrical and audio items tomorrow, up to £200 on selected large appliances and laptops and up to 25% on selected tvs.
Ed Connolly, buying director for John Lewis electricals and home technology, said: 'Black Friday has become a huge promotional event in America and we have also seen customers respond well to this day in the UK.