French city on alert after chemical plant blast

Schools have been closed in the French city of Rouen and residents warned to stay indoors after an explosion at a factory that manufactures toxic chemicals.

Smoke from the factory blaze is visible from miles away - and authorities have warned people to avoid the area.

Emergency alert sirens sounded in Rouen and nearby Petit-Quevilly, and residents in 12 areas around the city have been urged to stay indoors and limit their movements, as a precaution, because of the dangerous nature of the chemicals produced at the Lubrizol plant in Rouen.

The prefecture also issued a series of instructions to those in affected areas on Twitter.

The préfecture announced the closure of schools in Rouen, as well as Bois-Guillaume, Mont-Saint-Aignan, Isneauville, Quincampoix, Saint-Georges-sur-Fontaine, Saint-André-sur-Cailly, La Rue-Saint-Pierre, Saint-Germain-Sous-Cailly, Cailly, Bosc-Guérard-Saint-Adrien - all to the north of the city.

Officials also said that initial analysis of the chemical make-up of smoke from the fire showed 'no acute toxicity', but added that further updates would be made as tests were carried out through the day.

Some 200 firefighters are on the scene to combat the blaze that broke out in a storage facility in the early hours of Thursday. The fire was reported at around 2.50am. Shortly afterwards a series of explosions were heard across the city.

The alerts have been issued because the Lubrizol factory is a Seveso-class plant, due to dangerous chemicals produced there. Seveso is a European Union directive aimed at minimising the risk from major chemical accident hazards. It is named after the 1976 Seveso disaster in Italy, in which tens of thousands of people were affected by toxic chemicals from a factory explosion.

A 500m perimeter has been set up around the site. So far no casualties have been reported.

Dating back to the Second World War, the 4,500 sirens of the Réseau National d’Alerte are supposed to sound a warning in the event of a major incident, such as the one in Rouen.

The sirens are generally heard only at around noon on the first Wednesday of each month - when they are tested.

Official advice from the Ministry of the Interior says that, on hearing the siren, people are supposed to know about likely local dangers and move to avoid being affected.

In most cases this means to head for a closed area or room without windows or air-conditioning, block up any gaps round doors and air vents and switch on the radio to France Inter, France Info or local stations.

Read more: Only one in five know what siren means