French judges on Saturday handed preliminary charges of attempted murder to a man suspected of stabbing four young children and two adults in a French Alps park, an attack that reverberated across France and beyond.

The suspect is a 31-year-old Syrian refugee with permanent residency in Sweden. His name was not released.

The lead prosecutor, Line Bonnet-Mathis, told a news conference Saturday that the man was presented to investigating judges in the lakeside town of Annecy on Saturday and given charges of attempted murder and armed resistance. He is in custody pending further investigation.

The prosecutor said the victims are no longer in life-threatening condition after Thursday's attack in and around a playground. The children, between 22 months and 3 years old, remain hospitalised.

The six victims came from four different countries: France, Britain, the Netherlands and Portugal.

The suspect, a 31-year-old Syrian political refugee with permanent residency status in Sweden, has a 3-year-old daughter and wife living in Sweden, the prosecutor said.

He was examined by psychiatrists who deemed him fit to face charges, the prosecutor said. She said that the motive for the savage attack remained unclear, but it didn't appear to be terrorism-related.

Witnesses said they heard the attacker mention his daughter, his wife and Jesus Christ, according to the prosecutor, who said he had Christian objects with him at the time of the attack.

Police detained the suspect in the lakeside park in the town of Annecy after bystanders — notably, a Catholic pilgrim who repeatedly swung at the attacker with his backpack — sought to deter him.

French President Emmanuel Macron visited the victims and their families, first responders and witnesses Friday.

Macron said two young French cousins who were the most critically injured have stabilized, and doctors were "very confident.”

The wounded British girl “is awake, she's watching television,” Macron added. A wounded Dutch girl also has improved and a critically injured adult — who was both knifed and wounded by a shot that police fired as they detained the suspected attacker — is regaining consciousness, Macron said.

The seriously injured adult was treated in Annecy. Portugal's foreign ministry said he is Portuguese and “now out of danger.”

He was wounded “trying to stop the attacker from fleeing from the police,” it said. The second injured adult was discharged from a hospital, his left elbow bandaged.

The pilgrim, Henri, a 24-year-old who is on a nine-month walking and hitchhiking tour of France's cathedrals, said he'd been setting off to another abbey when the horror unfolded in front of him.

The attacker slashed at him, but Henri held his ground and used a weighty backpack he was carrying to swing at the assailant.

Henri's father said his son “told me that the Syrian was incoherent, saying lots of strange things in different languages, invoking his father, his mother, all the Gods.”

The suspect's profile fuelled renewed criticism from far-right and conservative politicians about French migration policies. But authorities noted that the suspect entered France legally, because he has permanent residency status in Sweden.

Sweden and France are both members of the EU and Europe's border-free travel zone.

He applied for asylum in France last year and was refused a few days before the attack, on the grounds that he had already won asylum in Sweden in 2013, the French interior minister said.