Shoppers line up outside a Wal Mart in Williston, Vt., Friday, Nov. 25, 2005, waiting for the doors to open at 5 a.m. for the traditional day-after-Thanksgiving sale

U.S. shoppers flocked to stores and malls Friday, as retailers offered deep discounts to get the Christmas shopping season off to a busy start.  Shoppers are taking home bargains, but shop-owners face a challenge in keeping up their sales during the four weeks until Christmas.

The annual shopping season begins the day after Thanksgiving, and the holiday weekend got off to a busy start here in Los Angeles, where hundreds of customers lined up outside some stores for early morning bargains.

Clerk: "Is everybody ready to shop?"

Customers: "Yes!"

One hundred thousand people were expected to shop Friday at the Glendale Galleria in suburban Los Angeles.

At a Wal-Mart near Seattle, extra police helped control overzealous shoppers who were desperate to buy discounted laptop computers. A police officer said several fights broke out.

A small melee also erupted when some customers cut into line at a Wal-Mart in Orlando, Florida.

With higher-than-usual prices for gasoline and heating oil, retailers had worried that shoppers would be reluctant to spend this year. In response, some stores have adopted aggressive marketing strategies. Macy's department stores are giving away a total of one million dollars in cash cards to their customers.

Among this year's most popular sale items are portable DVD players, flat-screen televisions and digital cameras.

The National Retail Federation says a recent drop in oil prices should give holiday sales a boost. The organization predicts that U.S. retail sales for November and December will approach 440 billion dollars, a six-percent rise over 2004.

The CEO of Federated Department Stores, the parent firm of Macy's, said he is cautiously optimistic.