Berlin- More than 90 people were harmed Saturday when carbon dioxide gas was released following a fire at a paint factory in the western Germany city of Moenchengladbach.

The accident happened as a result of a defect in the fire extinguishing system, which uses the gas to douse fires.

Thirteen people were treated in hospital. Those affected included factory workers, fire officers and local residents, who reported symptoms of dizziness and nausea.

Police sealed off an area of around a kilometre around the factory, ordering nearby residents to close their windows and to go to higher floors, as carbon dioxide is heavier than air.

The danger remained even after the leak in the fire extinguishing system was sealed. "The problem is that there is no wind at all. The carbon dioxide column is standing like a chimney up into the air," a fire officer said.

A helicopter was deployed in an attempt to disperse the gas, which is not toxic at low concentrations. (dpa)