Shopping frenzy struck the US as shoppers filled stores across the country in the traditional Black Friday ritual, on the first holiday day after Thanksgiving.

The fiercest shopaholics slept on sidewalks outside their favourite stores to be the first to benefit from the pre-Christmas sales.

Others profited from sales managers' impatience to see their budget turning from red to a profit-signing black colour - the reason for the name black Friday. Some stores opened their doors at midnight or even earlier on Thursday evening in the hope of cashing in.

"I ate my turkey dinner and came right here," Rasheed Ali, a 23-year-old New York City student holding a brand new 50-inch TV, told local reporters as he emerged from a Target store.

"I think it's better earlier. People are crazier later at midnight. And I get tired at midnight," Florida shopper Renee Ruhl, 52, told NBCNews.

Long lines, crowds and shopping hunger often resulted in episodes of violence.

Last year 20 people were injured, as a woman pepper-sprayed fellow shoppers waiting in line for the new Xbox in a California Walmart, claiming she was being pushed.

In 2008 a Walmart employee in the state of New York was killed by a crowd of about 2,000 shoppers that ran over him after having broken into the closed store.

It has been estimated that Americans are to spend a total of $11.4bn (£7.1bn) today alone.