French prosecutors say four men are the first to be charged in connection with the attacks in Paris earlier this month that left 20 people dead, including three assailants.
Paris Prosecutor Francois Molins said on Wednesday that four men aged between 22 and 28 were handed preliminary charges overnight of association with terrorism.
Three of them are suspected of having bought "equipment" for Amedy Coulibaly, who shot a policewoman to death on the outskirts of Paris and then killed four hostages at a kosher supermarket.
The attacks started with the January 7 massacre at the satirical weekly newspaper Charlie Hebdo. Coulibaly, and the brothers who attacked the newspapers' office, were killed by police.
The prosecutor said the four charged suspects were jailed until a further investigation.
Three of the four had criminal records and at least one met Coulibaly in prison, Molins said.
He said that authorities in France are working with other countries to search for other possible accomplices. Molins said investigators are trying to uncover who was responsible for the posthumous video of Coulibaly, which was edited and released days after he and the Charlie Hebdo gunmen Said and Cherif Kouachi were killed by police.
In the video, Coulibaly pledges allegiance to the Islamic State of Iraq and the Levant (ISIL) group and details how the attacks were coordinated by the three men.