The team, who are preparing for a friendly in Brussels next Tuesday against Portugal, had called off a session on Tuesday not long after the attack at the Zaventem airport and on a rush-hour metro train.
They had planned a session at 11h00 local time on Wednesday but decided on Tuesday night to also call that off. They were still considering a run out on Wednesday afternoon.
The game against the Portuguese, set for the King Baudouin Stadium, remains in jeopardy.
“We had been in contact with the Portuguese for much of Tuesday and also consulted several different security authorities, although understandably they have been absorbed with more urgent matters,” a statement from the Belgian football association KBVB said. “We will attempt to give more information as quickly as we can.”
Belgium, who will be one of the favourites for the European Championship in France later this year, had their last international against Spain in November cancelled in the wake of the Paris attacks.