By DEBORA REY
Associated Press

ASUNCION, Paraguay - Locked doors prevented or slowed the escape of supermarket shoppers from a fast-spreading fire that killed at least 318 people and injured hundreds, survivors said Monday. The market's two owners were detained for questioning.

But a television station, citing unidentified Interior Ministry officials, said some 364 bodies had been recovered. Independent Channel 4 Telefuturo also said 524 people were injured. The official injury toll is 276.

The cause of Paraguay's worst disaster in decades was not known, but police said they were investigating whether an exploding gas canister in the food court may have started Sunday's blaze.

The owners, a father and son, denied the doors were locked.

The fire tore through the bustling, three-story supermarket in a suburb of Asuncion, the capital, during lunch hour. The blaze collapsed one floor and engulfed the food court and parking garage. Investigators are trying to determine how many more were inside the building but escaped unharmed.

Esther Benitez, a 30-year-old cashier who suffered burns, said she at first found her way blocked as she tried to escape. "I ran toward the main door but it was locked," she told The Associated Press from her hospital bed Monday.

Some neighbors said they were forced to break windows to enter the supermarket because the doors wouldn't open.

"There were people crowded outside the main entrance using sticks and poles trying to open the door," said Raul Tamay, who rushed to the supermarket and found his brother, Hernan, who had been shopping inside.

"We couldn't get inside and the people couldn't get out," said Liliana Hernandez, 33, who lives next door to the Ycua Bolanos supermarket.

She said even firefighters, frustrated in their efforts to get inside, resorted to battering holes through a wall of her house to reach the supermarket. "They broke two giant holes in the wall to carry bodies out," she said.

Juan Pio Paiva, who owns the market with his son, dismissed speculation that the doors had been deliberately locked to prevent looting.

"The security guards confirmed that the doors weren't closed by them," he said, angrily. He said he "lamented" the disaster and insisted the building met safety standards.

Attorney General Oscar Latorre called on survivors to come forward to describe what happened. Authorities set up a table outside the supermarket - a pink-and-white building occupying nearly an entire city block - to question survivors and other witnesses.

"We need people to come forward and give testimony to help us get to the bottom of this," Latorre said.

At a nearby disco and sports club, army troops unloaded truckloads of wooden coffins at makeshift morgues. Tearful relatives filed in to identify bodies; funerals were held around the capital.

Rescuers continued to search for bodies Monday, but Police Chief Aristides Cabral said it appeared unlikely they would find more victims.

Cabral said rescue efforts were hampered by fears the building might collapse. Temperatures were still high in parts of the market.

The head of a volunteer fire brigade, Capt. David Rojas, said identification of many of the dead would go slowly. "We are finding badly mutilated bodies, in some areas only torn limbs," he said.

Eustaquio Colman, an Interior Ministry official, said some bodies recovered Monday were burned beyond recognition.

President Bush, Pope John Paul II and German Foreign Minister Joschka Fischer sent condolences to Paraguay. White House press secretary Scott McClellan said the U.S. Embassy and U.S. agencies are working with Paraguayan officials "to identify the emergency assistance that we can provide."

Neighboring Argentina sent a Hercules transport plane loaded with medicine; Spain was preparing to send in psychological counselors; Chile promised a C130 carrying doctors, medical supplies, and equipment to treat burns.

(Associated Press writer Pedro Servin contributed to this report.)