The fire on Monday in the central Marais arrondissement, popular with tourists, swept through a dilapidated building squatted in by some 40 Ivory Coast nationals. Four children - one a six-year-old thrown from a fourth-floor window by a desperate mother - died, along with three adults. Police said faulty wiring apparently installed by residents was probably to blame.

The tragedy followed a similar blaze last Friday, in which 17 Africans - 14 of them children - lost their lives in another Paris apartment block, also badly run down. In April, 24 immigrants died when their dingy hotel caught fire, allegedly because the supervisor's girlfriend lit candles in his room.

The series of tragedies has focused France's attention on the pitiful conditions in which immigrants - many of them from former African colonies - often live. Survivors of Monday's blaze said they shared just one lavatory for the whole building, and had to do their washing in the street because they had no water.

President Jacques Chirac expressed his horror at the latest fire, as he did for the last two. But he also vowed that his conservative government would take "strong initiatives" to prevent similar accidents in the future.

Although Mr Chirac did not elaborate, the Interior Minister, Nicolas Sarkozy, blamed the loss of life on immigration policies. "By accepting these people who, unfortunately, we can't offer work or housing, we find ourselves in a situation where we have these tragedies," he said. " All these squats and all these buildings have to be closed to stop these tragedies and that's what I've asked the police commissioner to do because we're talking about human beings living in unacceptable conditions."

Mr Sarkozy, who is expected to challenge Mr Chirac for the presidency in 2007 elections on a platform of tough security measures and economic liberalism, is spearheading a policy which aims to deport this year 23,000 of the estimated 400,000 illegal immigrants living in France.

But that tough position is being challenged by immigrant groups, civil rights activists and unions, which are calling for proper housing to be provided to prevent further fire deaths.

They held two protests yesterday and are planning a rally in Paris on Saturday to press their demands. The groups stressed that immigrants face hurdles to finding homes, ranging from racist landlords and a lack of money to an absence of visas for the paperwork. High property prices in France also force them into unsafe housing, they say.

According to one French charity, the Fondation Abbé Pierre, more than three million people in France live without basic amenities such as running water or heating.

Paris City Hall has started to renovate 1,000 residential buildings to increase the amount of low-cost housing available. It bought the fire-ravaged building in the Marais six months ago but had not started work because squatters remained despite an eviction order obtained in 2000.

City Hall has asked police to give visas to the surviving Ivorians so they can get other accommodation in the city and the gutted building can be made habitable.

Fatal fires in the French capital

FEBRUARY 1998

Eight people, including a pregnant woman and her nine-year-old daughter, die in two separate apartment fires in Paris.

DECEMBER 2001

Four people die in tourist hotel fire in the heart of the city.

15 APRIL 2005

Twenty-four people, including 10 children, are killed when their temporary accommodation in a budget hotel in the Opera district catches fire. Most are African immigrants.

26 AUGUST 2005

Seventeen west African immigrants die when their apartment block in the 13th arrondissement goes up in flames. Overcrowding is blamed.

29 AUGUST 2005

Seven immigrants, including four children, die when fire breaks out in a building where Ivory Coast nationals are squatting. Police believe faulty wiring may be to blame.