At least four people were killed by a gunman who took hostages in a kosher supermarket in eastern Paris, a police source told Reuters on Friday.
Explosions rocked a small printing firm in the village of Dammartin-en-Goele, northeast of Paris, and smoke poured from the building as the heavily armed forces mounted their assault as night fell.
The two terrorists launched a desperate escape bid, charging out of the building firing at the security forces before being cut down in their tracks, a security source said.
Meanwhile, in the east of Paris, gunfire erupted as police stormed the Jewish store, where at least one armed assailant had seized five hostages after two people were killed in a gun battle.
The gunman was also killed, security sources said, as terrified hostages were seen running out of the store.
The dramatic climax to the two stand-offs brought to an end more than 48 hours of fear and uncertainty in the country that began when the two brothers slaughtered 12 people at Charlie Hebdo in the bloodiest attack on French soil in half a century.
The hostage-taker in the eastern Porte de Vincennes area of Paris was suspected of gunning down a policewoman in southern Paris Thursday and knew at least one of the Charlie Hebdo gunmen.
French police released mugshots of the man, Amedy Coulibaly, 32, as well as a woman named as 26-year-old Hayat Boumeddiene, also wanted over the shooting of the policewoman.
The Porte de Vincennes area in eastern Paris was swamped with police who shut down the city's ringroad as well as schools and shops in the area.
In Dammartin-en-Goele, only 12 kilometres (seven miles) from Paris's main Charles de Gaulle airport, French elite forces had deployed snipers on roofs and helicopters buzzed low over the small printing business where the Charlie Hebdo suspects had been cornered early Friday.
Police sources said there was a "connection" between the supermarket gunman and Cherif and Said Kouachi, accused of carrying out France's bloodiest massacre in half a century at Charlie Hebdo.
Ahead of the stand-off, police had already exchanged fire with the pair -- orphans of Algerian origin -- in a high-speed car chase.