The investigation revealed “the threat of serious attacks that would target several emblematic places in Brussels and be committed during the end-of-year holidays,” the prosecutor’s office said.
Belgian media, citing anonymous official sources, added that the attacks were to be aimed at the police headquarters near to Brussels’s central square, the Grand Place, although official sources were still to confirm the precise targets.
A source, who spoke on condition of anonymity, confirmed that the main square was thought to be the focus of the planned attack: “On the Grand Place, there are a lot of people, as well as soldiers and police who are patrolling, as well as a police station nearby,” the source said.
Police and soldiers in Brussels have also been ordered to take special precautions to ensure their own safety, said Benoit Ramacker, spokesman for the Belgian government’s Crisis Centre.
Police and army patrols were greatly beefed up in Brussels following the Paris attacks, and Ramacker said a new official threat assessment conducted on Monday evening after the latest searches and arrests concluded the officers and soldiers deployed to protect others from extremist attacks might become targets themselves “in the exercise of their functions”.
The arrests came hours after the Belgian authorities announced that they were moving to terror alert Level 3, which would remain in force until next week, indicating that an attack is “possible and likely” – the status is just one notch below the highest Level 4 alert of “serious and imminent” which caused Brussels to be placed in complete lockdown following November’s attacks in Paris.
During house searches in Brussels and a neighbouring province as well as Liege, a total of six people had been taken in for questioning but four of them had been released, they said yesterday.
The remaining two, both understood to be male, were placed under arrest on charges including participation in the activities of a terrorist group as a leader or recruiter with the aim of committing terrorist offences as principal or secondary actor, the prosecutor’s office said.
Police found military clothing and Isil propaganda material but no weapons or explosives and the searches were not linked to the attacks in Paris in November, which killed 130 people, prosecutors said.
The prosecutor’s office also said computer material was seized and is being examined.
The prosecutor’s office said no additional details would be made public, but that the probe was not connected to the November 13 attacks in Paris, in which numerous suspects, including presumed ringleader Abdelhamid Abaaoud and fugitive Salah Abdeslam, had connections to Belgium.
Prosecutors said in a statement yesterday that they uncovered “serious threats of attacks targeting several symbolic sites in Brussels which would be committed during the New Year’s festivities.
On November 21, the terror alert level for the Belgian capital area was temporarily raised to its maximum level after authorities announced they had received credible information that an attack could be imminent.
Belgium has also been one of the leading sources in Europe for foreigners recruited to fight for Isil. In January, Belgian anti-terrorism units broke up what they said was an imminent attack on police by raiding a house in the eastern city of Verviers, killing two suspected jihadis and arresting a third.
Their main quarry, however, was not there: Abdelhamid Abaaoud, who went on to become the suspected ringleader of the attacks in Paris.
Brussels city leaders are expected to decide today whether the annual New Year’s Eve fireworks display, scheduled for another central square near the Grand Place, should go ahead as scheduled.