French prosecutors on Friday announced a formal investigation against two men with ties to Amedy Coulibaly who was gunned down by police after killing five people in Paris on Jan. 9. The men are believed to be criminally associated to Coulibaly, 32, who had pledged allegiance to the Islamic State militant group that’s laying siege to large parts of Syria and Iraq.  

The suspects have been identified publicly only as Said M., 25, whose DNA was found on a taser used by Coulibaly in the Hyper Cacher market, and Amar. R, 33, who texted Coulibaly hundreds of times over a four-month period and met him 10 times, “in particular on Jan. 5 and 6,” the prosecutor’s office said.

The market, which was heavily damaged during the shootout between Coulibaly and the police, is set to reopen on Sunday, according to the Times of Israel.

The opening of a formal investigation is the first step toward a criminal trial of the two men. French prosecutors now have six suspects in custody linked to the Jan. 7 attack on satirical magazine Charlie Hebdo, in which a dozen people were killed, and the Jan. 9 kosher store hostage-taking.

Authorities have suspected all along that the attackers in both raids must have had assistance because they were heavily armed, raising concern that the gunmen in these attacks were more than just lone-wolf jihadists.  

Coulibaly and the Charlie Hebdo attackers, Said Kouachi and his brother Cherif, were killed in standoffs with police. Coulibaly’s widow, Hayat Boumeddiene, was tracked to the jihadist-controlled Syrian border town of Tel Abyad on Jan. 10, her last known location. Coulibaly and the Kouachi brothers knew each other for years.  Police say the three met up a day before the Charlie Hebdo attack.

Police detained a dozen people on Jan. 16 in three suburban Paris raids, but most were released while four remain under investigation on suspicion they provided “logistical support” to the attackers, according to France 24.

Four suspects were detained on Monday, but two of them were later released. The other two – Said and Amar – were handed preliminary charges on Friday. Phone records indicate that Amar was near Coulibaly shortly before the kosher store attack. Amar and Said allegedly destroyed their mobile phone SIM cards on the day of the hostage-taking.