French authorities have issued European arrest warrants for a young couple who fled to Belgium after spiriting away their premature baby from a Paris suburb hospital, prosecutors said Friday.

Born eight weeks premature, the child named only as Santiago needs constant medical care to stay alive. But late on Monday evening — just 17 days after his birth — his parents aged 23 and 25 removed him from the neo-natal unit in the Robert Ballanger hospital in Aulnay-sous-Bois, northeast of Paris.

After appealing to the public for information with a nationwide kidnapping alert, authorities now say the pair fled with Santiago to neighbouring Belgium.

“Arrest warrants… for the parents have been published at the European level and more broadly via Interpol,” Eric Mathais, chief prosecutor in the Seine-Saint-Denis department, said.

Police and prosecutors said in a Thursday press conference they were “extremely concerned” but not “giving up hope” of finding Santiago alive.

They called on the parents to bring their child “immediately to the nearest hospital” for urgent care.

Two men and a woman linked to the parents were arrested on Tuesday morning in Seine-Saint-Denis.

The men were both charged with kidnapping and detaining a child and have been kept in custody, prosecutors said Friday.

They “have acknowledged accompanying the couple and their infant as they fled to Belgium before returning overnight,” prosecutors had said Thursday.

Meanwhile the arrested woman was charged with failing to report a crime, but released under police supervision.