French police searching an apartment where four suspected terrorists were arrested Monday have allegedly found electrical components that could be used to make bomb detonators.
The electrical components, which police say could have been used to detonate a bomb, were found hidden in a washing machine in the apartment in La Corneuve.
One investigator told the French news agency AFP that a real terrorist operation was being planned but was stopped in time.
Investigators at first thought the people were planning a chemical attack, but now believe they were planning to plant a bomb. It is not know when or where the bomb was to be placed.
Police found two gas containers in the apartment in the first raid Monday, according to the newspaper Le Parisien. They are said to be of the same type as those used in a series of bomb attacks in Paris in the late 1990's.
The police also found two flasks of chemicals, one of which has been identified as iron trichloride, which could also be used in a bomb.
Investigators say the four people detained are part of a terrorist cell and that they came closer to carrying out an attack in France than anyone has since since the September 11 attacks last year.
They have been identified as Mirouane Ben Ahmed, who has been wanted by police for two years; his wife, who is also of Algerian origin, another Algerian man and a Moroccan.
They were under surveillance in a judicial investigation into what is called the Chechen network. The Le Monde newspaper says investigators believe at least 20 French citizens of North African origin have passed through Chechnya recently for various types of training and coordination with other militants.