Investigators Monday cleared unexploded illegal fireworks from a marketplace where a chain reaction of blasts and flames killed at least 70 people as the inferno raced through stalls crowded with Christmas shoppers.

Another 45 people were injured in Sunday afternoon's mayhem in a congested street market, said Salvador Padillo, the Red Cross commander. Most were quickly released from the hospital and none was reported seriously injured.Red Cross spokesman Alfonso Manzo said early Monday that 70 bodies had been found. At least 12 of the dead were children, officials said.

The last seven bodies were discovered shortly after 3 a.m. (2 a.m. MST) in a fireworks storeroom. Many of the other dead were found in the rubble of candy vendors' stalls.

"It was a time bomb," said Elizabeth Diaz, a member of a union of market vendors. "There's hundreds of people who come here to sell them (illegal fireworks), they have for years. Why didn't the authorities come?"

Authorities said they had not determined the cause of the disaster, and witnesses disagreed on where the first explosion occurred.

But all said that after the first blast, explosions ripped like machine-gun fire through stalls where vendors had been selling skyrockets, Roman candles and other fireworks.

"At first it sounded like bullets. Then there were more and more and then the explosion," said Fernando Dominguez, who was working in a shoe store.

Selling fireworks to the general public is barred in Mexico City, but the law is widely ignored.

The fire ripped through the congested market and five adjacent buildings, which are half a mile from the Zocalo Plaza in the heart of Mexico City.

The area was crowded with shoppers buying food, looking for Christmas presents and for fireworks to celebrate the Day of the Virgin of Guadalupe, Mexico's patron saint, which is Dec. 12.

"People were running out of the market and screaming," said Oscar Cordero, 25, standing by the pile of debris that had been his stand and stock of calculators and other electronic goods.

The block on Corona Street was one of scores in the old downtown where vendors set up tables in the street. It is one of the busiest market areas in this city of 18 million and is most famous for the Mercado de Dulces, or Candy Market, one of the buildings that was partially burned.

Many people died when they were trapped in buildings along the street that caught fire. The fire spread to the five-story Candy Market, an apartment building and three other buildings.

After the fire was out, firefighters and sanitation workers used dollies to remove dozens of crates of unexploded fireworks from the area, and the work continued under floodlights through the night. The street was strewn with spent firecrackers, charred wood and comic books, twisted metal, tangles of high tension wires and glass from shattered windows.

Everado Gamiz Fernandez, a municipal leader, admitted that inspections in the market were not frequent and that there might be 2,000 fireworks vendors in his district.

"There aren't enough resources to inspect and watch here every day and night," he said. "They've always sold fireworks here."