An 84-year-old priest was killed and four other people taken hostage by two armed men who stormed his church in a suburb of Rouen in northern France.
The two attackers, who said they were from the so-called Islamic State (IS), slit Fr Jacques Hamel’s throat during a morning Mass, officials say.
Police surrounded the church and shot dead both hostage-takers.
French media named one of them as Adel K. One of the hostages is in a critical condition in hospital.
President Francois Hollande, visiting the scene, in Saint Etienne-du-Rouvray, said the attackers had committed a “cowardly assassination” and France would fight IS “by all means”.