Brussels, Reuters, 26 March 2016 – An empty apartment block on a quiet street turned out to be the perfect place for the three suspected Brussels attackers to prepare the home-made nail bombs used in Tuesday’s airport and metro attacks that killed at least 31 people.
In a building undergoing renovation, there were no near neighbors to notice them taking in large quantities of strong-smelling household chemicals, as well as a suitcase of nails, to concoct an unstable white explosive powder known as TATP, or triacetone triperoxide, that they later used in their attacks.
“Even if someone had stopped them, they could have said the materials were for renovation,” said Hassan Abid, an official at the local town hall, who was trying to determine why authorities had no knowledge of the men living illegally on the fifth floor.
Belgian investigators do not answer questions on the case.
Having moved in two months ago, the Belgian brothers Khalid and Brahim El Bakraoui used the apartment in the largely middle class borough of Schaerbeek as a laboratory-cum-hideout, from where Brahim and two other men took a taxi on Tuesday morning to the airport to commit their attacks.
Their choice of low-cost explosives — among ingredients are drain cleaner and nail varnish remover — apparent knowledge of chemistry and ability to set up in an apartment 15 minutes drive from the airport should offer clues about ISIS bombmaking methods to investigators struggling to understand how the Syria-based group built a violent network of radicalized young Belgians.
The ready availability of ingredients, compared to military explosives favored by older militant groups like the IRA in Northern Ireland or Basque separatists ETA in Spain, highlights the risks across Europe of more big attacks.
However, the need for premises to manufacture quantities of TATP over several weeks and the final mixture’s “use by” date of just a few days make the bombmakers vulnerable to the intensive search efforts of detectives on their trail. French and Belgian police have successfully found and neutralized bomb “factories”, most recently in the Paris suburb of Argenteuil on Thursday.
Militants have used fake identities and premises listed with municipal authorities as unoccupied to evade residency checks.
Brussels police failed to find the Schaerbeek flat in time, but were there shortly after the attacks, aided by the taxi driver who unwittingly took the three men to the airport.
Prosecutors uncovered 15 kg of TATP, as well as 180 liters of the chemicals needed to make bombs.