The attacker fled the scene after the shooting outside the church in Lyon, seriously wounding a Greek Orthodox priest, police said earlier.
A suspect has been arrested after a Greek Orthodox priest was shot and seriously wounded in the French city of Lyon, a police source has said.
The source could not confirm whether the person was the assailant.
The attacker fled the scene after the shooting outside the church, police said earlier on Saturday. Local authorities and prosecutors have said it was not yet clear what the person's motives were.
The priest was fired on twice at around 1500GMT (4:00 pm local) as he was closing the church, and he was being treated for life-threatening injuries, the police source said.
Another police source said the priest was of Greek nationality, and had been able to tell emergency services as they arrived that he had not recognised his assailant.
A Greek government official identified the priest as Nikolaos Kakavelakis.
There was no indication from French officials that the attack was terrorism-related. The French anti-terrorism prosecutor's office had not been brought in, as is normal when law enforcement officials suspect a terrorism link, France's BFMTV broadcaster said.
Thousands of soldiers deployed
Two weeks ago, a schoolteacher in a Paris suburb was beheaded by an 18-year-old attacker who was apparently incensed by the teacher showing a blasphemous caricature of the Prophet Muhammad during a class.
Depicting prophets is strictly avoided in Islam.
Muslims object to the cartoons on the basis that they were meant to provoke and insult the community at large. The publication of such caricatures is seen in the larger context of the French state's anti-Islam policies which have discriminated against people for eating Halal food and women wear the hijab.
While the motive for Saturday's attack was not known, government ministers had warned that there could be other attacks.
President Emmanuel Macron has deployed thousands of soldiers to protect sites such as places of worship and schools.
Prime Minister Jean Castex, who was visiting Rouen, said he was heading back to Paris to assess the situation.
A third person has been taken into police custody in connection with that attack, a police source said on Saturday. The suspected assailant was shot by police and remained in critical condition in hospital.