Earlier in the day, two armed men took five people hostage at the Saint-Etienne-du-Rouvray church in the Seine-Maritime commune.
According to the France Info news outlet, both attackers have been killed by the law enforcement.
The BFMTV broadcaster later reported that the dead hostage was a priest.
Visiting the scene of the attack Francois Hollande said that two man ‘claimed to be Daesh’.
The president also expresses support to catholics in France sying that’all catholics were attacked’.
Earlier, Pope Francis has expressed his horror at the ‘barbaric killing’ of the priest during the incident.
“The pope… shares the pain and horror of this absurd violence,” Vatican spokesman Federico Lombardi said as cited by AFP, adding that the attack created “immense pain and worry”.