ATH, Belgium, July 30 (AFP) - At least 15 people died and scores were injured Friday when a high-pressure gas pipeline exploded on an industrial estate near the Belgian town of Ath, Prime Minister Guy Verhofstadt said.
"There are 15 dead, 120 victims are being looked after, 12 of them in France... and at least three people are unaccounted for," Verhofstadt, who broke off a holiday in Italy to visit the scene of the blast, told reporters in Ath, 50 kilometres (30 miles) southwest of Brussels.
Five of the dead were local firefighters, he said. The day of the burial of the victims will be one of national mourning, with flags flown at half mast, he added.
Verhofstadt said it was too early to say what had caused the explosion.
"From what we know today, it was an accident. It will be up to the enquiry to tell us why (the explosion) was so serious."
Offers of help came in from France, Germany Luxembourg and the Netherlands as well as from the European Union Commission. Pope John Paul II sent his condolences.
The pontiff said in a telegram to the papal nuncio in Belgium he was "praying for the numerous injured and their families, so that they will find comfort in their difficulties."
An estimated 200 people were working in the area of the blast which sent flames leaping dozens of metres into the sky and produced thick clouds of smoke.
Some victims were thrown hundreds of metres by the force of the explosion, according to one local official, while Belgian television said debris had been found six kilometres (four miles) away. Authorities in Ath set up a temporary mortuary.
The health ministry said that a gas leak had been detected at 8:30 am (0630 GMT) on the Ghislenghien industrial estate, home to about 30 businesses, near a motorway passing through Ath and that "when emergency services arrived, there was an explosion." A service station also blew up, and a diamond factory under construction was destroyed.
Fluxys, a subsidiary of the French Suez group that operates the gas transport system in Belgium, said the pipeline between Zeebrugge and the French border was immediately isolated and that the leak was under control.
Local journalist Christel Millien said she heard the blast in her office in central Ath.
"Everyone panicked a bit. We thought it was an earthquake. We phoned the fire service and they said they thought it was gas explosion," she said.
She arrived 15 minutes later at the site of the blast to find "a scene from the apocalypse. I am not being funny, it was really the apocalypse.
"Cars had been burned out. The firemen were trying to control this horrible situation."
She said she saw a huge crater, and cars destroyed up to 500 meters (yards) away.
Several firemen, who had arrived when the strong smell of gas had been detected, died in the blast, she said. Some were thrown a hundred metres (yards). Millien`s father, himself a firefighter, had found the body of a colleague, she said.
Implementing a disaster plan, Belgian officials called on local people to stay inside and to keep doors and windows closed. Verhofstadt flew back from a vacation in Italy, while Defence Minster Andre Flahaut and Interior Minister Patrick Dewael went immediately to the scene.
Residents were asked to stay in their houses with windows and doors shut. Later, Verhofstadt said there had been no pollution and that there was no risk of a further explosion.
The motorway from Brussels to Tournoi and Lille was shut, but reopened later in the day.