The Paris prosecutor's office says one person has been detained in the investigation into an attack on a church that left a priest dead and was claimed by ISIS.
A prosecutor's office spokesman said the person was detained on Tuesday, but gave no details on the identity or location.
The Paris prosecutor's office oversees investigations involving terrorism.
Two attackers took hostages in a church in the Normandy town of Saint-Etienne-du-Rouvray during morning Mass, slitting the throat of Fr Jacques Hamel before being killed by police. Authorities are trying to determine whether they had accomplices.
