NANTES, France — Police ordered several thousand people to leave their homes Thursday and seek shelter from a drifting cloud of toxic gas released by a fire in a fertilizer warehouse, officials said.
The "extremely toxic" cloud, 12 miles long and several miles high, contained chloride and nitrous vapors that could burn respiratory tracts, the Environment Ministry said.
Officials declared a state of emergency, but the toxic level of the cloud dissipated to a safe level by late afternoon.
Interior Minister Charles Pasqua told a news conference in Paris that 24 people were treated for injuries after the gas escape. He added that the incident was likely to cause pollution of the Loire River.
The yellow-colored gas belched from the warehouse for most of Thursday, but officials said the fire had been brought under control.
More than 1,000 police and soldiers were pressed into service to take people out of the path of the cloud, which medical experts said could have the same effect as mustard gas, used during World War I. They said it could kill if inhaled in considerable quantities.
Thousands of children were taken to Nantes soccer stadium for safety, roads in the region were closed and train service was suspended.
Several thousand people living in the communities of Saint Herblain, Indre and Coueron, all west of the Loire, were urged to seal off their cars and leave their homes under an emergency evacuation system.
The gas release began early Thursday when the fertilizer warehouse caught fire near the Nantes harbor. Police believe the fire was caused by a short circuit.