Anger at Toulouse blast location

Around 400 firefighters worked through the night

The Mayor of the city of Toulouse in southern France, Philippe Douste-Blazy, has called for all potentially hazardous factories and plants to be relocated away from areas where people live.

Mr Douste-Blazy made the demand as rescuers continued to search for survivors in the ruins of a chemical fertilizer plant, which exploded on Friday.

The damage could have been greater had the fire reached a nearby explosives plant

After working throughout the night emergency services have recovered four more bodies, bringing the death toll to 29.

Around 700 people were also injured in the blast, around 50 of them are in a serious condition and Mr Douste-Blazy has warned that the death toll is likely to rise.

Cause unknown

The authorities say that while the explosion appears to have been an accident, it is still to say for sure what was the cause.

The AZF chemical plant, located about 3 km (two miles) outside the south-western city of Toulouse, was levelled by a blast with the strength of a 3.2 magnitude earthquake.

When it was originally built in the 1920s, the factory was far from inhabited areas, but as the city grew, that soon changed.

The Green Party has long argued that the factory should be closed down.

Anger

"The initial emotion has given way to anger," said Gerard Onesta, an ecologist who represents the region in the European Parliament. "The deaths and injuries could have been avoided."

"The aberration that allowed a dangerous chemical industry to exist in the city of Toulouse must be denounced," he added.

The explosion scattered debris over a wide area and carved a 50m (164 feet) wide crater into the ground.

An inquiry is under way into what caused the blast. French radio reported that some of the workers had made a mistake while mixing chemicals.

AZF was the biggest fertiliser producer in France.

French President Jacques Chirac and Prime Minister Lionel Jospin have both visited the scene.

Twisted ruins

BBC correspondent Christopher Bockman, at the site, says the factory is now little more than a twisted tangle of metal and rubble.

Hundreds of residents ran into the streets in panic after the blast and police sealed off the area, fearing a cloud of fumes seen after the explosion could be poisonous.

People later reported experiencing stinging eyes and throats and a strong smell of ammonia.

A number of people are still missing

Witnesses said the force of the blast blew out windows and cut telephone lines to the area.

Sandra Muller, a mother of three, told the Associated Press: "We thought it was a plane exploding. All the houses trembled."

Hundreds of local residents have been left homeless by the explosion and they are being given temporary lodging in local gymnasiums.

And 70 schools have also been damaged.

The authorities have appealed for construction workers and craftsmen to volunteer to help repair the homes and damaged public buildings.