THE Black Friday sales have been criticised by police after violence broke out among crowds vying for bargains.

Chaos was reported in many UK stores as several major supermarkets, clothing  and electrical retailers offered reduced prices both online and on the high street.

As a result, retail analysts have warned that the surge in online shopping could create delivery problems ahead of the Christmas season.

According to the Centre for Retail Research (CRR) online sales are expected to increase by 18 per cent, as new phone apps have made shopping quicker and more accessible.

Couriers are also expected to feel the strain as government officials estimate that there is a shortage of 60,000 truck drivers, partly as a result of new certification laws. CRR director, Joshua Bamfield said: "I think there will be an acute problem this year."

Stores including Tesco, Argos and Game began selling discounted products from midnight on Thursday, with enormous crowds appearing in the early hours of  yesterday morning in scenes described as "absolute carnage" by shoppers.

At least three people were arrested in Greater Manchester yesterday, and one woman was injured by a falling television at the height of the chaos.

Police were also called to three Tesco branches in London following reports of large crowds in Edmonton,  Willesden and Surrey Quays.

Retail worker Shaun Thompson, 21, said he saw a member of staff with a black eye after a disturbance at Tesco in Stretford, Manchester. "I got there at about 10pm and there were queues gathering already. Then at about 10 minutes to midnight [just before the store opened] it just went mad. People were shouting their heads off and a few minutes after that it exploded.

"People were ripping covers off the shelves, they were fighting with each other, fighting over TVs. I have never seen anything like it in my life. It was quite scary."

Sir Peter Fahy, chief constable of Greater Manchester Police said: "The events of last night were totally predictable and I am disappointed that stores did not have sufficient security staff on duty. This created situations where we had to deal with crushing, disorder and disputes between customers. It does not help that this was in the early hours when police resources are already stretched."