Two suspects - believed to be brothers Cherif and Said Kouachi who are implicated in Wednesday's attack on Charlie Hebdo magazine - are dead after police stormed the print works building they were holed up in north-east of Paris.
A sudden burst of gunfire followed by two heavy explosions were reported just before 4pm (GMT).
AFP has reported that a hostage was released alive.
The Création Tendance Découverte printworks is in the town of Dammartin-en-Goele - 25 miles north-east of Paris (map below).
Reports earlier on Friday said police had made contact with the two men and were negotiating.
Witnesses said suspects had a "grenade-launcher" and other weapons in the vehicle.
Flights at the nearby Charles de Gaulle airport were diverted to its southern runways.