One of Britain's most senior police officers has hit out at stores after "Black Friday" promotions sparked chaos and violence around the country.
The US post-Thanksgiving tradition has become more popular on this side of the Atlantic in recent years.
Peter Fahy, chief constable of Greater Manchester Police, criticised shops for failing to provide enough security after fights broke out and huge crowds caused crushes.
Officers were called to a number of supermarkets overnight as thousands of customers sought bargains on what retailers hope will be one of the busiest shopping days of the year.
At least two people were arrested and a woman was hurt after being hit by a falling television.
Some outlets were forced to shut to restore order.
The Chief Constable 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.
"Across Greater Manchester large supermarkets already make significant demands on policing through calls to shoplifting, anti-social behaviour and thefts of fuel from their petrol stations - much of which is preventable.
"We just ask these stores to work with us to reduce the demands on policing and reduce the risks of disorder and crime."
A number of shops opened at midnight, boasting massive discounts on a range of goods, but shoppers described scenes of "carnage" as people scrambled for the best deals.
GMP said two people were arrested at Black Friday sales events after officers were called to seven Tesco stores across the area. A post on the force's Twitter feed said: "Keep calm, people!"
Shortly before midnight there were reports of several hundred people trying to enter Tesco Central Park in Wigan. Two men were ejected before control was regained.
The Tesco at Ellesmere Shopping Centre in Walkden was closed after a crowd of more than 500 people turned up.
The Tesco Extra in Stretford was closed after fights broke out between shoppers trying to get their hands on sale stock.
