At least 13 people have been killed after a fire broke out at a bar in Rouen in northern France, according to a French interior ministry statement.

The victims, who were primarily between the ages of 18-25 had gathered for a private birthday party at the Cuba Libre bar.

At least another six people have been injured - one of who is described as being in a life-threatening condition - after the fire broke out at around midnight.

A senior French police official said the fire was sparked when candles on the birthday cake ignited the polystyrene ceiling of the basement room where the celebrations were taking place.

The victims were poisoned by a toxic mix of gases released by the burning plastic, the official added.

Rouen mayor, Yvon Robert, said the fire was "very brief", adding that the birthday party was a "moment of joy for those involved that ended tragically".

At its height 80 firefighters battled the blaze.

Bernard Cazeneuve, the French interior minister said the cause of the fire was being investigated.

Some early reports claimed there had been an explosion, but the deputy prosecutor at the site, Laurent Labdie, said the noise reported by neighbours was the sound of windows exploding from the heat.