An 84-year-old priest was killed Tuesday at a church in northern France where two armed assailants took five hostages and were subsequently killed by police.
The hostage takers were "neutralized" by police while leaving a church, Interior Ministry spokesman Pierre-Henry Brandet said without giving details on possible motives for the attack.
One hostage was killed and an injured person remained "between life and death," Brandet said, adding that the other three were safe.
IN a statement calling for peace, Archbishop Dominique Lebrun of the nearby city of Rouen said that Father Jacques Hamel had been killed.
The anti-terrorism section of the Paris prosecutor's office took over the investigation into the hostage situation that began at about 9:45 am (0745 GMT).
Brandet said areas inside and around the church were being checked for explosives.
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.
France is on high alert after a series of terrorist attacks, the most recent one on Bastille Day in the southern city of Nice that left 84 people dead.
"We are in a period where everything is possible; the worst is possible," Georges Fenech, a conservative lawmaker who headed the parliamentary inquiry into the November 13 terrorist attacks in Paris, told BFMTV broadcaster.
Prime Minister Manuel Valls said he was, "horrified by this barbaric attack at a church in Seine-Maritime. All of France and all Catholics are wounded. We stand together."