ASUNCION: Survivors of an inferno in a crowded supermarket said locked doors slowed their escape from the fast-spreading fire that killed at least 311 people in Paraguay's worst disaster in more than half a century.

Hundreds more were injured, many with serious burns, after the blaze swept through the multilevel Ycua Bolanos supermarket on the outskirts of the capital, Asuncion, while it was crowded with shoppers midday Sunday.

At least 311 people were killed, Interior Minister Orlando Fiorotto announced at midday after workers searched the charred supermarket in the morning.

The nation's Health Ministry also said 276 people were injured, including 70 victims in intensive care with critical burns or breathing problems.

Paraguay has announced three days of mourning for the dead while struggling to find answers to the South American nation's worst tragedy in decades.

President Nicanor Duarte Frutos said on television late Sunday that he would push for a rapid investigation into the causes of the tragedy "so that those responsible are punished with the full force of the law."

Investigators will be probing reports that Sunday shoppers were trapped inside after the supermarket locked its doors to stop people from looting.

"There are several witnesses who saw how they shut the doors to the supermarket and we also confirmed that the emergency exit was soldered," Paraguay's Police Chief Humberto Nunez said.

Three owners of the Ycua Bolanos supermarket and three security guards are in police custody, but denied that the doors had been locked.

The fire swept through the busy supermarket on the outskirts of the city at midday on Sunday when it was packed with shoppers. Officials said the blaze was caused by a gas explosion near the food court.

Flames engulfed a parking lot underneath and several charred corpses were found in their burnt cars.

Rescue workers were still searching for bodies inside and many of the injured were in critical condition, he added.

Paraguay, a country of 6 million, called the fire its worst tragedy since a 1930s war with neighbouring Bolivia that killed thousands.

The government declared Monday a day of national mourning and suspended all official activities and classes.

The magnitude of the fire stretched the public services. Local hospitals were running short of burn treatment medicines.

Doctors made urgent calls for medical supplies and neighbouring Argentina has already sent a Hercules transport plane loaded with medication and bandages to Asuncion.

Television showed images of a surviving baby with a burned face whom rescuers said had been trampled by people as they fled the fire.

They were still looking for family members to claim the infant yesterday.

Families went to a makeshift morgue in a sports club on the outskirts of the city in a desperate search for relatives who had been at the popular supermarket.

(China Daily 08/03/2004 page1)