The inferno, one of the deadliest blazes in the French capital in 30 years, destroyed the six-story one-star Paris-Opera hotel, located behind the upmarket Galeries Lafayette department store and near the historic Garnier opera house.

As an inquiry got under way, a police source said the cause of the fire at the budget hotel — used both as temporary public housing for needy families and by bargain-hunting tourists — was “undoubtedly accidental.”

Witnesses described scenes of panic as hotel guests jumped or threw their children from the upper floors of the burning building in desperate efforts to save their lives.

A firefighter at the scene said seven of the victims died when they leapt from windows to escape the flames. One official said the death toll would have been lower had residents remained in their rooms and not tried to get out.

Eleven of the more than 50 others hurt have suffered serious injuries, including burns, multiple fractures and smoke inhalation, police said.

Among the injured were French, Senegalese, Portuguese, Ivorian, American, Ukrainian and Tunisian nationals. No information was immediately available about the identities of the dead.

French President Jacques Chirac called the blaze “one of the most painful catastrophes that has ever plunged Paris into mourning”, adding: “This drama gives us all a feeling of horror and has deeply upset us.”

Officials said in addition to a handful of tourists, 80 people were staying at the 32-room budget hotel in rooms rented by the city and charitable organizations for families in need, many of them immigrants.

Former residents of the hotel denounced their living conditions, saying the rooms were dirty, roach-infested and simply uninhabitable.

Paris police chief Pierre Mutz said the hotel did not appear to have any safety problems, and that the high death toll could be explained by the sudden spread of the fire, which caused widespread panic.

Firefighters said the only way out of the hotel was the main entrance, but the staircase down was quickly engulfed in flames and many residents were trapped on upper floors.

They added that safety regulations did not necessarily require additional exits, and that the building had been inspected last month.

More than 250 firefighters and emergency personnel rushed to the scene in the city’s ninth district after the fire broke out at about 2am.

Firefighters had the blaze under control 90 minutes later, but the last flames were only extinguished just before 6am.

An emergency medical center and a makeshift morgue were set up in Galeries Lafayette in storerooms near the ground-floor cosmetics department, but the store opened as usual to shoppers.