The article in the latest issue of the group’s online magazine Dabiq also credited the other two, the Belgian El Bakraoui brothers, with a lead role in organizing the Paris attacks.
Warning of more operations to come, it said: “Brussels, the heart of Europe, has been struck.”
Najim Laachraoui, a 25-year-old Belgian who blew himself up at Brussels airport on March 22, had “traveled the long road to France” after fighting in Syria since 2013.
“It was Abu Idris who prepared the explosives for the two raids in Paris and Brussels,” it added, using Laachraoui’s nom de guerre and calling him “very intelligent”. Investigators have suspected former engineering student was the cell’s bombmaker.
His fingerprints were found on suicide vests used in Paris on Nov. 13 and at a Brussels apartment where militants had made a homemade explosive known as TATP. It was from there that he and two other men took a taxi to the airport.
One of them was the other airport suicide bomber, Brahim El Bakraoui, 29, an armed robber on parole. Dabiq said had become a believer while in prison and on his release, with his brother Khalid, had bought weapons and made plans for an attack.
Khalid El Bakraoui, 27, who blew himself up on a metro train at Maelbeek station in Brussels’ EU district, also took up the cause in prison, the article said, describing him as a “natural leader” who had a “vivid, life-changing dream” while jailed for a carjacking.
“All preparations for the raids in Paris and Brussels started with him and his older brother,” Dabiq said.
“These two brothers gathered the weapons and the explosives. After the blessed raid in Paris, he saw another dream, which motivated him to carry out an istishhadi (martyrdom) operation.”
Along with notes on the three suicide bombers, Dabiq published an account of Mohamed Belkaid, a 35-year-old Algerian, who was shot dead by police on March 15 in a raid on an apartment in the Brussels suburb of Forest. That raid was the first in a chain of events that included the Brussels attacks and more arrests.
Belkaid had reached Europe from Syria with Laachraoui, the article said, confirming investigators’ conclusions that the two men traveled together posing as Syrian refugees last summer and were driven to Belgium by Salah Abdeslam, a prime suspect in the Paris attacks who was arrested three days after the Forest raid.
Without naming those who escaped from the apartment when police moved in, Dabiq said Belkaid stayed to hold off Belgian and French officers, wounding several. Investigators think Abdeslam may have been among those who got away that day.
Mohamed Abrini, an associate of Abdeslam, and someone who accompanied the suicide bombers to the airport, has said since his capture on April 8 that Abdeslam’s arrest had prompted the group to bring forward an attack and to strike in the Belgian capital rather than, as planned, again in France, prosecutors said.