PARIS (AFP) - Mamoudou Gassama, the 22-year-old Malian "Spiderman" feted for saving a child hanging from a balcony in a daring rescue that won him global acclaim, took his first step towards French citizenship Tuesday (May 29) and joined the fire brigade as accolades continued to pour in.

Wearing white sweatpants and a black cap, the hero of a rescue video which shows him climbing four storeys of an apartment block in Paris with his bare hands in less than a minute, appeared slightly overwhelmed by the media furore as he filed his application for legal residency in the Paris suburb of Bobigny.

Hailing the bravery of the youth who had been living in France illegally, the head of the local authority, Pierre-Andre Durand said: "How can anyone fail to be impressed by what he did, not admire it?

"He helped someone in danger, which is not such a common thing in our society."

Gassama became an overnight sensation after the video of him plucking a four-year-old boy to safety Saturday went viral.

On Monday he was honoured by President Emmanuel Macron with a medal for bravery, the promise of citizenship and the offer of a job with the fire service.

Gassama arrived in France via Italy and the perilous Mediterranean migrant route. His official permit allowing him to work will arrive within a month, and his citizenship papers in about three months, officials said Tuesday.

The athletic Malian also visited a fire station to sign up for a 10-month internship with the Paris fire and rescue services, expected to pay close to 600 euros (S$935) a month.

'Could have been worse'

The family of the young boy he saved thanked him Tuesday for his quick thinking.

The boy's mother learned the news of the rescue on Reunion Island - the French Indian Ocean territory where she and the father were born and where she still lives.

Reacting to Gassama's intervention on Antenne Reunion radio late Monday, the woman, who was not identified, said: "We can only thank him and thank heaven he was so reactive."

She said French police phoned her to tell her the news. "Then I saw video on the Internet. But I should not have watched it because you know it's your son in the video."

Just half an hour earlier she had spoken to both father and son in a video call, she said. "Things could have turned out much worse so I am relieved," she said, adding that she was impatient to be reunited with her son and husband.

The boy's father, who had been living alone with him in Paris, had left him alone to go out to the shops and then remained on the street to play Pokemon Go, according to French investigators.

The boy's paternal grandmother, who like his mother lives in Reunion, told RMC radio Tuesday that she was "very moved" by the images of the rescue and sent "huge thanks" to Gassama.

"He's really a hero," she said. "He did not stand by and watch, he saved my little sweetpea."

The child's mother, who had planned on moving to Paris in June along with the couple's second child, aged one, is due to travel on France on Tuesday, the BFM news channel reported.

The father, who was arrested on charges of neglecting his parental duties, was released from custody and reunited with his son on Monday under the supervision of social services.

The mother said her husband, who is in his 30s, was "shaken" by the incident.

While saying she could not justify his actions she said "it could have happened to anyone".

The Paris prosecutor's office said he had admitted his guilt and expressed "profound regret".