Authorities filed manslaughter charges Tuesday against an owner of a Paraguayan supermarket and five others for a massive fire in the store that killed at least 464 people, local media reported.

The indictments in Paraguay's worst disaster in decades came after investigators said that a security guard told them that when Sunday's fire broke out, the doors were ordered locked to prevent theft.

Juan Pio Paiva, the store's co-owner, denied that the doors had been deliberately locked and said the building met safety codes.

Channel 13 television reported that a judge had charged Paiva with involuntary manslaughter and ordered him imprisoned while the investigation moved forward. A business associate of Paiva and four security guards had also been charged, but that the status of Paiva's son, a co-owner, awaited a decision by the court.

Officials said the death toll had risen to 464 and that 409 people remained hospitalized.

Dozens of families searched for lost loved ones as investigators questioned the store's two owners, a manager and four security guards about whether the doors had been ordered locked to prevent people from leaving without paying.

The lunchtime blaze broke out at the three-story supermarket in a suburb of Asuncion, the capital. Flames swept through the Ycua Bolanos supermarket, food court and parking garage, causing a floor to collapse. Officials say they are checking reports that an exploding gas canister could have started the flames.

Prosecutor Edgar Sanchez, who is leading the investigation, said a security guard told authorities that at the outset of the fire he received orders over a radio to lock the doors to prevent theft.

Sanchez said the guard "didn't know" who gave the order. "He couldn't identify the voice that spoke to him over the radio," the prosecutor said.

Officials said they were trying to piece together survivor accounts that locked doors impeded or slowed shoppers trying to escape.

As funerals and burials were held across the capital, the mood remained edgy. Authorities evacuated a second Asuncion supermarket Tuesday after reports of a gas leak.

At the site of the fire, firefighters and others continued searching for victims. Dozens of family members gathered to look over badly burned bodies. Others held up photographs, hoping that rescue workers might recognize them.

"I'm looking for my mother! Where is she?" shouted Carlos Montiel, sobbing. Unable to identify her among the bodies, he frantically yelled a description of her: "She's tall, brown, and has black hair.

Larmina Gimenez, right, and two law student volunteers hold up pictures of her relatives missing after the Ycua Bolanos supermarket fire in Asuncion.