A huge explosion at Venezuela's biggest oil refinery has killed at least 26 people and halted production for two days, officials say.
At least 80 people were also injured in the blast which started a fire at the Amuay plant in Falcon state in the north-west of the country.
State Governor Stella Lugo said nearby houses had been damaged by the blast. The fire is said to be under control.
The refinery, one of the biggest in the world, produces 645,000 barrels a day.
Ms Lugo said there was no risk of further explosions.
Among the dead is a boy of 10.
Venezuelan Vice-President Elias Jaua, who travelled to the area in western Venezuela, said 17 of the victims were members of the National Guard stationed at the plant.
He added that military air ambulances had been dispatched to help evacuate the injured.
President Hugo Chavez has declared three days of national mourning.
Analysts say refineries in Venezuela, South America's biggest oil producer, have suffered from a long list of problems including power failures and accidents.
Energy Minister Rafael Ramirez confirmed operations at the plant had stopped but he expected them to resume by Monday.
He said that Venezuela had enough fuel supplies to guarantee continued exports and domestic supply, according to the Associated Press news agency.
Troops secured the area and were helping oil workers inspect the damage.
Mr Ramirez said the blast had occurred at 01:11 (05:41 GMT) on Saturday and had been caused by a gas leak.
"The gas cloud exploded, igniting at least two storage tanks and other facilities at the refinery," the energy minister told state TV.
"It was a significant explosion, there is appreciable damage to infrastructure and to houses opposite the refinery."
"We are deploying our whole fire service team, all our health team, the whole contingency plan on the orders of [President Hugo] Chavez to first of all care for the people affected by this emergency," Governor Lugo said on state TV.
Amuay, on the Paraguana Peninsula, is part of the Paraguana Refinery Complex, which also includes the adjacent Cardon refinery.
It is one of the biggest refinery complexes in the world with an overall capacity of 955,000 barrels per day, Reuters news agency notes.