French President Emmanuel Macron on Friday said the health of the preschool children badly wounded in a mass knife attack by a Christian Syrian refugee was "heading in the right direction," as police questioned the attacker.

Four children – aged between 22 months and three years old – were stabbed on Thursday in a playground in the Alpine town of Annecy, a normally idyllic lakeside spot popular with tourists. Two pensioners were also wounded during the assault.

Macron, who has called the attack an "act of absolute cowardice," visited the hospital in Grenoble where three of the four children are being treated, before heading to nearby Annecy.

"The doctors are very confident," Macron told the police and paramedics who responded to the aftermath of the attack. He also thanked the emergency responders.

While France was in shock over the blood-curdling attack, there was a deluge of praise on social media for rescue workers and a man hailed as a hero for chasing the attacker out of the area. 

Prosecutors insisted they did not see a terror motive, but the rampage intensified tensions in France over immigration, with right-wing politicians seizing on the suspect's origins.

Macron and his wife Brigitte arrived in the southeastern city of Grenoble, where three of the children are being treated, and are to visit those who have "contributed in helping and supporting them," the presidency said.

"Everything that I was told is heading in the right direction," he said in Annecy after visiting the wounded toddlers in hospital, adding that news on their condition was positive.

He added after the visit: "Attacking children is the most barbaric act there is" but also made clear his "pride" over the work of rescuers.

The fourth child, a Dutch citizen, is in a Swiss hospital over the border in Geneva. She is "out of danger", the Netherlands' Foreign Minister Wopke Hoekstra said. 

One of the young victims is British and the others French.

Meanwhile, one of the two pensioners caught up in the attack told Reuters he had been sitting on a park bench when the attacker approached on the run.

"He probably wanted to create one more victim," said Youssouf, who asked to withhold his family name.

'Pray for the children'

Macron also met a man named Henri who is being hailed as a hero for chasing the attacker from the playground. The management and philosophy student, a young Catholic pilgrim who has identified himself only as Henri, came face-to-face with the assailant and used his backpack as a shield as he sought to block the attack. 

"Pray for the children, I am doing fine," he wrote on Instagram as the hashtag #MerciHenri trended on social media.

"All I know is I was not there by chance," he told the CNews television network. "It was unthinkable to do nothing ... I followed my instincts and did what I could to protect the weak."

His Facebook and Instagram accounts were flooded with messages giving thanks for his bravery.

A Catholic mass will be held in Annecy Cathedral in tribute to the victims and their families later on Friday, church authorities said. An impromptu shrine emerged overnight at the park with people placing candles, flowers and messages. 

"We are not prepared for these kinds of events," said local Leo Ganassali, 21, as he laid flowers. "I came as a child to play in this park and to see it in mourning is very, very tough."

A video of the attack, taken by a bystander and verified by Reuters, showed the assailant jump a low wall into a children's playground and repeatedly lunge at a child in a stroller, pushing aside a woman who tried to fend him off.

The attacker, dressed in black and carrying a blade around 10 centimeters (four inches) long, could be heard shouting "in the name of Jesus Christ," according to a video taken by a bystander and seen by AFP.

Details of the suspect

Regional prosecutor Line Bonnet-Mathis said the detention of the suspect, named as Abdalmasih H., who is under investigation for attempted murder, had been extended for further interrogation after a psychiatric examination. 

She has said there was no indication that terrorism was the motivation and that the suspect was under investigation for attempted murder.

Police have arrested a 31-year old Syrian national who was granted asylum in Sweden 10 years ago, Prime Minister Elisabeth Borne said on Friday.

He had entered France legally, she said, and was carrying Swedish identity documents and a Swedish driving license. Sweden and France are both members of the Schengen Area, the world's largest passport-free zone which allows the unrestricted movement of people between 26 European countries.

Recently divorced from a Swedish national and in his early 30s, the suspect had previously lived for 10 years in Sweden where he was granted refugee status in April, security sources and his ex-wife told AFP.

"He called me around four months ago. He was living in a church," his ex-wife said, adding that he left Sweden because he had been unable to get Swedish nationality.

French Interior Minister Gerald Darmanin told broadcaster TF1 that "for reasons not well explained he had also sought asylum in Switzerland, Italy and France."

It emerged that his application in France was rejected last Sunday as he already enjoyed refugee status in Sweden. Darmanin described the turning down of that application and the stabbings as a "troubling coincidence."

Witnesses described the assailant running around the park on the banks of Lake Annecy wearing a bandana and sunglasses, apparently attacking people at random. Armed police arrested him at the scene.

'Time of emotion'

France has suffered a series of attacks in the last decade or so, most of them by Islamic extremists.

Most recently, the beheading of a teacher in broad daylight in 2020 near his school in a Paris suburb by a radicalized Chechen refugee led to a wave of shock and a national debate about the influence of radical Islam in deprived areas.

Thursday's attack spurred fresh debate of France's immigration and asylum policy.

"It seems like the culprit has the same profile that you see often in these attacks," the head of the right-wing Republicans party, Eric Ciotti, told reporters at parliament. 

Far-right National Rally (RN) figurehead Marine Le Pen meanwhile told French radio that France should "regain sovereignty" on immigration.

But government spokesman Olivier Veran said such debates were premature "when we are in the time of emotion, when the kids are on the operating table."

Prime Minister Elisabeth Borne invited "everyone to show dignity in these circumstances."

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