Belgian authorities asked Monday for the public's help in finding a man who is believed to be an associate of Paris attack suspect Salah Abdeslam and who, according to a media report, may have helped make suicide bombs used in the French capital.
The 24-year-old Belgian man, identified as Najim Laachraoui, was known to have left for Syria in February 2013. But traces of his DNA were found in a house and an apartment in Belgium that are thought to have been used by the Paris terrorists before their attacks.
He has also been identified as the man who used a fake Belgian identity card in the name of Soufiane Kayal when he was controlled in Hungary in September together with Abdeslam, Belgian prosecutors said in a statement on Monday.
Laachraoui is being "actively sought," they added.
His DNA has been found on at least two suicide belts that were used last November in the attacks on the Stade de France football stadium and the Bataclan concert hall, the broadcaster RTBF reported.
The Paris attacks, which also targeted restaurants and cafes, left 130 people dead and hundreds injured. Laachraoui may have made some of the suicide belts used, RTBF said.
Belgian federal prosecutor Frederic Van Leeuw refused to comment further on Laachraoui during a press conference with visiting French prosecutor Francois Molins on Monday afternoon.
Molins used the opportunity to call for Abdeslam to be handed over to France, after his arrest in Belgium on Friday.
"You know as I do that the French investigating judges have issued an arrest warrant [for Abdeslam]," Molins told journalists in Brussels. "It is now up to the Belgian justice system, and it alone, to decide on this question."
But he recalled that there is "a high expectation from the French justice system, and especially from the victims, to be able to obtain that Salah Abdeslam explains himself before French judges."
French President Francois Hollande met on Monday afternoon with survivors and victims' families at the Elysee Palace in Paris. Representatives from associations of victims' families also attended the meeting after having criticized France's anti-terrorism policies.
Molins said it could take as much as three months for Abdeslam, 26, to be handed over to France.
The French prosecutor has said that Abdeslam intended to carry out a suicide bombing at the Stade de France stadium during the Paris attacks, but then backed out.
Abdeslam's lawyer has said that he plans to take legal action against the French prosecution service for breach of confidentiality. Molins, however, brushed aside the suggestion, saying that he was "serene" about the matter.
Van Leeuw said Belgian authorities are still waiting to see if Abdeslam will cooperate with their investigation. He was interviewed several times on Saturday, but was not "in good shape" after being injured during his arrest, the Belgian prosecutor said.
When asked about Abdeslam's appearance, Van Leeuw said he would not have recognized him.
It is still unclear where Abdeslam was in the time between the Paris attacks and his arrest, the prosecutor said. Abdeslam was arrested in the same Brussels neighbourhood where he had previously lived.
His arrest came three days after another man sought in connection with the Paris attacks was killed in a shootout with police at an apartment in the southern Brussels neighbourhood of Forest.
Weapons and Abdeslam's fingerprints were found in that flat, prosecutors have said. RTBF reported on Monday that detonators were also recovered.
Van Leeuw said investigators may never know exactly what was planned, but added: "To find foreign fighters with weapons in a house, I don't think that was to have a picnic."
Belgian Foreign Minister Didier Reynders said on Sunday that Abdeslam was "ready to restart something in Brussels," without giving further details.
In Paris, meanwhile, the Belle Equipe restaurant reopened its doors on Monday, four months after having been targeted during the November attacks, the BFMTV broadcaster reported. Nine people were shot dead while sitting outside the restaurant.
The Bataclan concert hall remains closed, but is expected to reopen by the end of the year following a renovation.