Two men face preliminary terrorism charges in France after hundreds of texts and DNA evidence linked them to the Paris gunman who killed four people at a kosher supermarket and a policewoman.

The two men were handed preliminary charges for participation in a terrorist group with the intent to commit crime.

Prosecutors said Amar R, a jailhouse acquaintance of Amedy Coulibaly, exchanged more than 600 texts with Coulibaly over five months and met him on January 5 and 6, just before the killings at the Charlie Hebdo satirical newspaper and the Hypercacher supermarket that left 20 people dead, including all three gunmen.

DNA from the second man, identified as Said M, was recovered from a stun gun in Coulibaly's belongings at the market, the prosecutor said.

Said M and Amar R contacted each other more than 1,200 times between February last year and January this year and saw each other regularly, prosecutors said.

The statement said the two men destroyed their telephone microchips on January 9, the day Coulibaly and brothers Said and Cherif Kouachi were killed in separate stand-offs with French security forces.

Two other people taken into custody at the same time, including a policewoman, were released, the prosecutor said. They had been suspected of links with Coulibaly.

Europe 1 radio reported that the kosher grocery is expected to reopen on Sunday for the first time since the attacks. The printing office where the Kouachi brothers holed up for hours before coming out shooting at police remains closed.