Following a meeting of the country's National Security Council, Belgian Prime Minister Charles Michel announced this morning (Saturday 21) that the government was raising the terrorist threat in the country's capital to level 4, the maximum.
Belgian daily, Le Soir, reports Michel as saying that the decision had been taken, "following reports of a similar risk to the attacks in Paris." He added that the major concern was the risk of armed attacks, "in several places by several individuals".
Details of the threat remain unclear. However, sources close to the security services told this website that it may relate to a possible ‘revenge’ attack by the last remaining fugitive from the Paris attacks, Salah Abdeslam.
Officially, Belgian authorities remain tight-lipped. Michel has said the security situation will be reassessed tomorrow morning (Sunday).
Extra troops and police began entering Brussels early Friday evening. They have become a highly visible armed presence, patrolling outside public buildings and busy shopping areas throughout the city.
Although initially shocked, most people have reacted stoically to the military clampdown. One local tweeted that "If ever the sign "keep calm and carry on" is justified again, it is today in #Brussels"
Meanwhile, breaking media reports say bomb-making equipment as well as explosives have been discovered in Molenbeek. The neighbourhood, close to the city-centre, is suspected of being a breeding ground for terrorist extremism and is where at least two of the Paris attackers lived.
Michel refused to respond to the Molenbeek bomb-factory reports, saying he did not want to jeopardise, "ongoing investigations".
With most people staying indoors, large parts of downtown Brussels are deserted. Michel explained that the suspected prime targets were the obvious ones, "Shopping malls, shopping streets, public transport and generally those places where many people are coming together."
The city's metro stations will remain closed at least until tomorrow, while trams and buses with part-underground routes may experience delays or cancellations.
Rail services are running normally, although Schuman station in the heart of the EU district has been closed down. Airports are functioning normally, at a level 3 security state.
Many major tourist attractions are also closed and tonight’s Heysel concert with veteran Belgian rocker, Johnny Hallyday has been cancelled.