UPDATED: Two men armed with knives killed a priest after taking several people hostage at a French church, before they were shot dead by police.
Two knifemen claiming to be from Islamic state took several hostages during mass
They killed the 85-year-old priest Jacques Hamel by slitting his throat
Three churchgoers were also injured, one of them seriously
The attackers were shot dead by police
President François Hollande described it as a "vile terrorist attack"
Counter terror judges have been called in to investigate
Isis then claimed responsibility for the attack
Two knifemen slit the throat of an 85-year-old priest at a church in northern France on Tuesday in a hostage-taking drama that President François Hollande has described as a "vile terror attack".
Reports say the men, who according to the president "claimed to be from Isis", entered the church via a rear door at around 10am on Tuesday during mass.
Priest Jacques Hamel, aged 85, two nuns and two worshippers were taken hostage, while another nun was able to escape and raise the alarm.
Five people were inside the church when it came under attack, Interior Ministry spokesman Pierre Henry Brandet said.
He said the church was surrounded by France's anti-gang brigade the BRI, which specialises in kidnappings.
The priest was then killed after having his throat cut, while another parishioner was also attacked in the same way. The victim is said to be fighting for their life in hospital.
According to Le Parisien newspaper, the two men then came out of the church firing at police with at least one gun, before being shot dead by officers. One police officer was injured in the calf.
With France on high alert after a spate of recent terror attacks, most feared the hostage-taking was simply the latest in a growing line of attacks by jihadists.
Their fears were realized when Isis claimed responsibility for the attack via its news agency Amaq.
when the specialist counter-terrorism judges were swiftly placed in charge of the investigation.
Then president François Hollande described it as a "vile terror attack" and that the atttackers "claimed to be from Daesh" (using the Arabic name for the Islamic State group.)
The French President François Hollande, who is originally from Rouen, and Interior Minister Bernard Cazeneuve arrived at the scene at about 12:40pm.
France's Prime Minister Manuel Valls expressed his "horror at the barbaric attack" in the early afternoon.
"The whole of France and all Catholics are wounded. We will stand together," he wrote on Twitter.
French far-right politician Marion Marechal Le Pen, the niece of Marine Le Pen, tweeted: "They're killing our children, assassinating our police officers, and slitting the throats of our priests. Wake up!"
Pope Francis voiced his "pain and horror" at the hostage-taking, according to the Vatican.
The archbishop of Rouen, Dominique Lebrun, urged all non-believers to join those of the church in "calling to God".
"The Catholic Church can take up no other weapons that prayer and fraternity between men," he said in a statement.
News of the priest's death has sent shockwaves through the local community.
Eulalie Garcia, who runs a beauty institute on the same street as the church, knew the priest. She said Hamel had been her bible studies teacher when she was a child.
"My family has lived here for 35 years, we always knew him," she told l'Express newspaper. "He was someone who was very appreciated in the town. He was very inconspicuous, he never liked putting himself first.
Tuesday's incident comes nearly two weeks after Tunisian Mohamed Lahouaiej Bouhlel mowed down a crowd of people celebrating Bastille Day in the southern city of Nice, killing 84 and injuring over 300.
The attack was the third major strike on France in 18 months and was claimed by the Islamic State group.
In April 2015 the threat against churches in France was made clear when it was revealed student Sid Ahmed Glam, 24, planned to open fire on parishioners at a church to the south of Paris.
Police were able to intercept him after he apparently shot himself in the foot by mistake, but not before he had killed fitness coach Aurelie Châtelain.
The church where the attack took place. Photo: Google Street View