PARIS — The French authorities said on Friday that they had discovered a third body in the wreckage of an apartment after the police raid that killed Abdelhamid Abaaoud, the Belgian militant suspected of planning the Paris terror attacks.

Mr. Abaaoud’s cousin Hasna Aitboulahcen, 26, also died in the raid Wednesday on an apartment in the suburb of St.-Denis; her passport was found in a handbag inside. The third person who died in the raid has not yet been identified, said Agnès Thibault-Lecuivre, a spokeswoman for the Paris prosecutor.