The 6-year-old boy thrown from the 10th floor of London’s Tate Modern art gallery is a French tourist who was visiting the British capital with his family, police said Monday, as they asked witnesses of the “shocking incident” to come forward.

The child, who landed on a fifth-floor roof of the world-famous gallery Sunday afternoon, remains in stable but critical condition at a hospital with his family, Metropolitan Police said.

“We are providing around the clock support to the little boy’s family as they wait for more news on his condition and our priority remains to determine what led to yesterday’s events,” senior investigating officer John Massey said in a statement.

A 17-year-old boy was initially stopped by members of the public on the 10th floor viewing platform and then arrested by police on suspicion of attempted murder.

Police are treating the case “as an isolated incident with no distinct or apparent motive,” Massey said.

“This was a truly shocking incident, and people will understandably be searching for answers.”

But, he added, there was no link between the young victim and the teen suspect — neither of whom were named publicly.

Massey said anyone who witnessed the incident, but rushed out in shock afterward, should contact investigators.

“My team is also very keen to talk to you if you witnessed a male whose behavior seemed out of place, suspicious or worrying, in the hour or two before the incident in or near the gallery,” he said. “It may be that this is something which has only just come back to you.”

One witness, Mark Welte, on Monday told the BBC he was on the observation deck when he heard a commotion and loud “primal scream.”

“Someone said someone had thrown a child over. I leapt up and looked over the rail and I did indeed see a child down below there,” he said.

“The child’s mother then tried to climb the rail. I restrained her and pulled her back.”

Other witnesses said they heard the distraught mom cry out: “My son! My son!”

The art museum is the UK’s most popular tourist attraction, drawing 5.9 million visitors in 2018.

It was closed following the incident Sunday but open on Monday. A spokeswoman said the gallery’s 10th floor viewing platform would remain closed for the time being.