Bury them discreetly? Hand them back to their families? Return them to the country of origin?
Knowing what to do with the remains of the assailants involved in last month's Paris attacks is proving to be a conundrum for French officials.
The law envisages several scenarios, says Francois Michaud-Nerard, head of funeral services for the city of Paris.
"Either the families ask for their remains or they don't. If the families ask for their remains, the deceased have the right to a burial in the place where they lived, or where they died, or where the family has a burial plot."
If the families do not wish to hold a funeral, it is up to the local authorities in question to do so.
In any case, even "if there is no obligation to have an anonymous grave, that would be in everybody's interest", he said.
Officials fear that such a grave could become a site of "pilgrimage" for other extremists.
Seven gunmen and suicide bombers were killed on November 13, but so far, only four have been formally identified.
Of the three who blew themselves up outside the Stade de France national stadium in Saint-Denis, one has been identified as French-born Bilal Hadfi, 20, who lived in Belgium.
Two of three who were killed after attacking the Bataclan concert hall have been identified: Samy Amimour, 28, and Omar Ismail Mostefai, 29, both French nationals.
And Brahim Abdeslam, 31, another French national living in Belgium, blew himself up outside a bar on Boulevard Voltaire.
Questioned by AFP, the mayors of the Paris suburbs of Drancy, where Amimour lived, and Courcouronnes, where Mostefai was born, and Saint-Denis where three suicide bombers blew themselves up, said they had not been informed of any plans to bury them.
Alexandre Luc-Walton, lawyer for the Amimour family, said his clients "were waiting for news from the forensic institute. They still do not have permission to bury him".