At least 15 people were killed and more than 100 injured when the explosion ripped through the underground pipeline in the industrial zone of Ghislenghien, near the town of Ath, 40 km southwest of Brussels.

The chain of explosions, described by one witness as a "mini-Hiroshima," destroyed two factories, leaving a large crater between the plants. Bodies and debris were scattered over a 500-metre radius around the disaster site and scorched a wide area.

"There were bodies in parking lots, in the fields; burnt out cars in an area half a kilometre wide," fire department spokesman Francis Boileau said. "It looks like a war zone,"

"There were people fleeing who I am sure we will find too late in the fields several hundred metres away," he said.

The regional civil protection agency gave a provisional toll of 15 dead and at least 100 wounded but said the figures could rise because 24 people were severely burned and in critical condition.