Two people who held five hostages at a church in northern France on Tuesday morning were "neutralized" as they left the church armed, an Interior Ministry spokesman said.
One hostage had been killed and another was "between life and death," Interior Ministry spokesman Pierre-Henry Brandet told broadcaster BFMTV.
The anti-terrorism section of the Paris prosecutor's office took over the hostage situation that began around 9:45 am (0745 GMT), the office said.
French President Francois Hollande was en route to the site of the church in Saint-Etienne-du-Rouvray in the north-eastern region of Upper Normandy accompanied by Interior Minister Bernard Cazeneuve.
It was not immediately clear what the motives for the hostage-taking were.
French media reported that a priest was killed in the hostage situation, during which two nuns were also held.
France is on high security alert after a series of terrorist attacks, including an truck attack on Bastille Day in the southern city of Nice that left 84 people dead and the killing of a police couple at their home in June. Both of those incidents were claimed by the Islamic State.
A hostage situation is under way at a church in northern France, local officials said Tuesday.