At least 20 people were hurt when a woman used pepper spray on other shoppers at a US supermarket during Black Friday.
Police said she was trying to keep them away from the goods she wanted.
The incident happened in a crowded Los Angeles area Walmart as shoppers hungry for Black Friday deals were let inside. Black Friday is the day after Thanksgiving Day and many shops open early to launch the Christmas shopping season.
Officials said around half of the injuries were caused by crowd jostling after the spraying. Police are still looking for the woman.
In 2008, a security officer working at a Walmart on Black Friday was trampled to death by a crowd.
Long lines of shoppers snaked around malls across the US today as some chain stores pushed their openings and specials up to Thanksgiving night, hoping to get a jump-start on the busiest day of their year.
While Black Friday has been the busiest day for years in terms of traffic at stores, it does not always mean that sales will soar for the season. Despite brisk sales right after Thanksgiving, total holiday season sales fell in both 2008 and 2009 when the recession took its hold on America's wallets.
The National Retail Federation, an industry trade group, expects 152 million people to hit stores this weekend, up 10.1 per cent from last year. Yet it only expects sales for the full November-December holiday season to rise 2.8 per cent, after climbing 5.2 per cent in 2010.
Luxury chains, such as Saks Inc, and those catering to lower-income shoppers, such as dollar stores, are seen as the big winners this season, while mid-market retailers are expected to have a tough time winning over shoppers without the cache of the high-end set or the deep discounts others offer.
Opening early appeared to work, judging from the long lines at stores such as Toys R Us, Best Buy, Walmart and Target.
Even after a Toys R Us in New Jersey had been open for nearly an hour this morning, there was still a line of about 300 people waiting to get inside.
"It was like 'Club Toys R Us' - one cart out, one cart in," said Charlie O'Shea, a senior retail analyst at Moody's.
After a woman walked out of the store with a large Little Tikes toy in her cart, the man waiting for her outside gave her a high-five, Mr O'Shea said.
"People are looking for the big ticket item which is where they're going to get the most bang for their buck," said Mr O'Shea, who also saw "a smattering of carts" with small goods.
Retail executives and analysts are predicting a more competitive season than 2010. US unemployment still remains at 9 per cent, European debt woes are weighing on the stock market and consumer confidence remains spotty.
Wal-Mart Stores, Old Navy, which is part of Gap, and Kmart, owned by Sears Holdings, were among the few retailers open on Thanksgiving.
Walmart began offering Black Friday deals last night while Target Corp, electronics chain Best Buy and department store chains Macy's Inc and Kohl's Corp opened at midnight - their earliest starts ever.
Other retailers, including JC Penney, opened early this morning as they did last year.
Retailers from Amazon.com to Walmart were also offering online deals as Thanksgiving has become one of the biggest online shopping days of the year.
Some shoppers said that they feel as if the economy is back in a recession, leading them to change their shopping habits.
"Because of the recession, we are not going to shop as much," said Desiree Schoolfield (49), a public service professional from Queens, who was shopping at the Toys R Us in Times Square.
About 1,000 people were waiting in line at the opening of the Target in Farmingdale, New York.
At Macy's in Herald Square, four Occupy Wall Street activists chanted "boycott Macy's" and "stop supporting big corporations" even as about 9,000 people lined up to shop at the store.
Reuters
