By Terril Yue Jones

CHONGQING, China (Reuters) - Wal-Mart stores in Chongqing reopened to surging crowds on Tuesday, two weeks after being shut down by local authorities for violating food and product standards.

About one hundred shoppers were waiting outside a Walmart in the Nan'an district of Chongqing and rushed inside when the doors opened about 10 minutes early. Other Walmart stores were jammed with shoppers in the food aisles, lured by special discounts on a range of goods.

"The prices are cheaper than before they closed," said a young woman eyeing a billboard advertising the sale outside the store in the sprawling central Chinese city's Jiulongpo district.

"Potatoes are cheaper, 78 fen (12 U.S. cents) per half-kilogram," said the woman, who would not give her name but said she worked in the service industry.

Wal-Mart reopened its 13 stores here after being forced to shutter them after Chongqing authorities discovered branches of the world's largest retailer selling regular pork labeled, and priced, as organic pork.

It was the latest in a string of 21 violations dating back to 2006, and authorities, who said they were dissatisfied with Wal-Mart's previous responses, ordered a two-week closure of all the chain's stores in the city.

Many of the earlier infractions were vague, such as lemon candy, women's jackets or washing machines that "did not meet standards," according to the Administration of Industry and Commerce's Chongqing Bureau.

But some citations, including selling dairy products and juice after expiration dates, evoked food safety worries, a keen concern in a country that has seen repeated scandals involving food tainted with toxic ingredients.

Wal-Mart did not protest the closures and says it used the fortnight to strengthen its monitoring processes and training.

In a statement issued on Tuesday, Walmart China also said it has created a "fast food inspection lab" in its stores.

"Walmart is committed to Chinese customers, and is dedicated to compliance with all the standards and requirements," said company spokesman Anthony Rose in the statement.

Walmart China's CEO Ed Chan and its head of human relations resigned last week, but the company did not link it to the store problems and said that both left for personal reasons.

The Administration for Industry and Commerce said on Monday it would start a three-month food safety inspection program, sending inspectors to Walmart and other hypermarket chains to promote a safe food environment.

LONG LINES, NO ORGANIC PORK

Walmart staff at three of the reopened stores said the crowds on Tuesday were considerably larger than usual.

At all three, shoppers snapped up large containers of soy sauce, cooking oil and rice, which were on sale. They examined eggs, with the farm's name stamped on each one, selected shelled peanuts one by one from a giant pile, and gutted fresh rabbits themselves at a large table.

Half an hour after the Jiulongpo store opened, 13 of the food section's 48 checkout lines were humming.

One lengthy queue of some 80 people snaked around displays with people lined up to buy grapefruit-like pomelos.

"They're so cheap," said Lu Zhongxiu, a 53-year-old retired purchasing agent who picked up half a dozen. "In my neighborhood, they're 3 yuan per 500 grams. These are only 3.50 yuan each, and they're at least a kilogram."

Lu's cart was loaded down with more than she could carry, but she said she would take the Walmart store's free shuttle bus home.

Conspicuously absent from displays at Jiulongpo was organic pork, which triggered the latest Wal-Mart crisis.

"It's very hard to obtain," said a Walmart worker with the name tag Taiyong. "You have to produce it up in the mountains. There isn't a lot available."

(Editing by Don Durfee)