A total of 209 homes and 11 businesses were damaged, and a National Guard post was destroyed in an oil refinery blast in western Venezuela, Vice-President Elias Jaua said on Saturday night.

He said 18 of the victims were National Guard soldiers.

Other government officials went on television saying the gas leak had led to the blast and that the fire was being brought under control. President Hugo Chavez ordered an investigation and declared three days of mourning in the country.

Some oil experts and government critics were raising questions, saying they believe there hasn't been sufficient maintenance at refineries and that the situation could be making such incidents more likely.

Refinery manager Jesus Luongo denied that, as did Chavez, who spoke to journalists near the refinery on Sunday.

The president said investigators haven't determined what caused the disaster.

"Lack of maintenance? Who can, who can say that right now with any seriousness? Nobody," Chavez said. He said he had spoken personally with some of the military officers who were on duty at the time.

"They tell me that very night, in the rounds that were made a few hours earlier, no substantial leak was detected," Chavez said.

On Saturday night, dozens of people who had fled their homes in the neighbourhood of La Pastora returned to streets covered in rubble, twisted scraps of metal and puddles of spilled fuel.

Among the world's largest refineries

Gabriela Nunez, a housewife, returned to her home to gather belongings, saying she was worried about looters who had stolen goods from nearby stores hours after the explosion.

"That forced us to come back, even though we're afraid, to save what can be saved and secure our houses," Nunez said.

Flames rise after an explosion in the Amuay refinery near Punto Fijo, Venezuela. (Ariana Cubillos/Associated Press)

More than a day after the blast, the flames were still raging on Sunday, sending up a thick column of smoke.

Amuay is among the world's largest refineries and is part of the Paraguana Refinery Complex, which also includes the adjacent Cardon refinery. Together, the refineries process about 900,000 barrels of crude per day and 200,000 barrels of gasoline.

Oil Minister Rafael Ramirez said the country has enough fuel in storage, "10 days of inventories," to keep the Venezuelan market fully supplied. He said fires were still burning in two fuel storage tanks but that other "process areas" of the refinery were otherwise unaffected.

Once the flames are completely extinguished, Ramirez said, "we have the ability to restart our refinery in two days."

Starting over

Restarting will be a challenge for Gonzalez, who picked through what remained of his family's apartment, sweeping away debris with a broom. Broken glass littered the floor along with fragments of the shattered walls.

The shop on the first floor was also destroyed, but Gonzalez and his brother and sister-in-law all survived with only minor injuries.

"I'm happy to be here telling this story," Gonzalez said, his hand covered in a bandage and with stitches on his arms. "Material things, although they cost us a great deal to obtain, aren't worth much when you compare them with life."