Cherif Kouachi, one of the two brothers who killed 12 people in an attack on France's Charlie Hebdo magazine, has been buried in an unmarked grave near Paris under tight security.

Kouachi was buried late last night at a cemetery in Gennevilliers, where he used to live, officials said.

No relatives attended the funeral and the grave was unmarked to avoid it becoming "a pilgrimage site" for Islamist militants, the official said.

"His wife did not wish to take part in the funeral. He did not have anyone. It was extremely calm," the official said.

Cherif's widow had asked for him to be buried alongside his older brother Said in the cemetery at Gennevilliers, about 9km northwest of central Paris.

However, local mayor Patrice Leclerc blocked the request since Said was not a resident of the area.

Mr Leclerc said he had "no legal choice but to allow the burial of Cherif Kouachi to go ahead".

Said was buried the previous night in the northeastern town of Reims, where he had lived for around two years.

His funeral was held under heavy police protection and with a handful of family members present, according to a well-informed source.

His wife decided not to attend the burial in order to keep it secret, said her lawyer Antoine Flasaquier.

"She is now relieved that her husband has been buried with discretion and dignity," the lawyer said.

Under French law, relatives must request permission for a burial from the local town hall, which has to be granted if the individual lived or died in the area, or has a family burial plot there.