There are huge discounts available on everything from electricals like TVs, tablets and other gadgets to designer watches, clothing and toys.
In London, Tesco staff and queuing shoppers made calls to the police at the Glover Drive Store in Edmonton, the BBC reports. Police also attended two other Tesco stores in Willesden and Surrey Quays as well as an Asda store in Edgware at around midnight.
They were also called to stores in Wigan, Manchester and Cardiff as crowds became increasingly unwieldy.
More police enforcement turn up at Gabalfa Tesco in Cardiff. pic.twitter.com/APt9XlxtKa— Richard Jones (@Richard12545678) November 28, 2014
Police called out as fights break out around the country in Tesco's Black Friday sale...shares down 2% pre-market ;-) pic.twitter.com/UnNekHRrtZ— RANsquawk (@RANsquawk) November 28, 2014
In a statement, the Metropolitan Police said:
Met Police officers have responded to a number of reports tonight, 27 November of large crowds gathering to bag a bargain at the ‘Black Friday’ sales.Officers have worked with store staff to ensure that sale-goers were able to enter and exit the stores safely. No persons have been injured at any of the locations as a result of the overcrowding. Officers have now withdrawn from the stores.
Greater Manchester Police added:
At least two people arrested at #BlackFriday sales events already this morning. Keep calm people!— G M Police (@gmpolice) November 28, 2014
Some 47 per cent of shoppers have said that they would take part in Black Friday this year, according to figures from retail information group Verdict.