Said Kouachi, one of the two brothers who launched a deadly attack against French satirical magazine Charlie Hebdo last week, has been buried in an unmarked grave.
Said Kouachi, 34, was buried secretly late on Friday in the eastern city of Reims, where he had lived before the attack.
The mayor of Reims said he had opposed the burial, fearing a grave could become a shrine, but had been forced to accept it by law.
Attacks in Paris killed 17 people last week, 12 of them at Charlie Hebdo.
On January 9, two days after attacking the magazine, Said Kouachi and his younger brother Cherif were killed by police at an industrial estate north of Paris.
There has been no announcement on plans for burying Amedy Coulibaly, who killed four people at Jewish supermarket HyperCacher in Paris on January 9 and is suspected of killing a policewoman in the French capital a day earlier.
Earlier in the week, Reims mayor Arnaud Robinet said he would “categorically refuse” a family request for Said Kouachi to be buried in the city.
Arnaud Robinet said he did not want “a tomb that could become a shrine for people to gather around or a pilgrimage site for fanatics”.
However, on January 17 he said he had been forced by the government to accept the burial.
“He was buried last night, in the most discreet, anonymous way possible,” Arnaud Robinet told French TV.
The city said in a statement: “Given the risk of disturbance of the peace and in order to quickly turn the page of this tragic episode, it was decided to do the burial quickly.”
A lawyer for Said Kouachi’s widow said she had not attended the burial for fear that journalists would follow her and the location of the grave would be discovered.