Police in France have launched a manhunt after a Greek priest was shot with a sawn-off shotgun while closing the doors to his church.
The priest is in a critical condition fighting for his life after the attack in Lyon on Saturday.
The Lyon prosecutor's office said a man who was arrested shortly after Saturday's shooting was released after they found no evidence of his involvement.
Police are continuing to search for those behind the attack, which saw the priest shot twice.
France was already on high alert after three people were killed in a terrorist attack at a church in Nice on Thursday.
It was one of four attacks that took place across the country that same day, including one in Lyon which saw police arrest a man of Afghan origin after he tried to board a train armed with a 30cm knife.
The victim was named as Father Nikolaos Kakavelakis by the Greek Orthodox Holy Diocese of France, which said the 52-year-old was due to return to Greece soon.
“We pray for a speedy recovery and unequivocally condemn all forms of violence,” it said.
The motive for Saturday’s shooting remains unclear, police said. The Lyon prosecutor has opened an attempted murder probe, and anti-terrorism police are not investigating.
It is understood the priest had been involved in a long-running legal dispute with a former monk who was convicted of defamation.
President Emmanuel Macron has deployed thousands of soldiers to protect sites such as places of worship and schools in the wake of a surge of violence across France.
A spate of attacks has taken place after the killing of teacher Samuel Paty, who showed students cartoons of the Prophet Mohammed as part of a lesson on free speech.
Mr Macron, who has vowed to stamp out radical Islamism in the country, sought to quell some of the anger directed at France on Saturday by saying he could understand how Muslims might be shocked by the cartoons.
Since Mr Paty's killing, French officials have re-asserted the right to display the cartoons, and the images have been shown at marches staged in solidarity with the dead teacher.
This has prompted an outpouring of anger in parts of the Muslim world, with some governments accusing Mr Macron of pursuing an anti-Islam agenda.
On Saturday, French authorities arrested two more people, aged 25 and 63, in connection with the Nice atrocity.
Tunisian migrant Brahim Issaoui, 21, is suspected of carrying out the attack.
Three others detained earlier over suspected links to Mr Issaoui remain in custody.
Mr Issaoui was shot by police multiple times and is currently in a serious condition in hospital.
Investigators have so far been unable to question him and his motive remains unclear.
"It is still too early to say if there were others complicit, what his motivations were in coming to France and when this idea took root in him," a source close to the inquiry said.
Investigators believe Mr Issaoui travelled illegally to Europe via Italy's Mediterranean island of Lampedusa on September 20.
He arrived at the mainland Italian port of Bari on October 9 before coming to Nice just two days before the attack.