Belgium maintained the highest terror alert level for the capital of Brussels on Sunday, indicating a "serious and imminent" threat of attack, NBC News reported.
The security measures came amid an international manhunt for Saleh Abdeslam, a potential accomplice to the Paris attacks last week, who was believed to have crossed into Belgium after the terror spree.
Abdeslam's brother, Mohamed, issued a fresh appeal Sunday for him to give himself up to police, telling RTBF television "We would rather see Salah in prison than in a cemetery.
Heavily-armed troops and police have deployed across Brussels since "precise" warnings of a Paris-style terror attack prompted the Belgian government to raise the capital's terrorism alert level to its highest status on Saturday.
The Brussels connection to deadly attacks in Paris last week has been of particular focus as investigators work to determine how a network of primarily French and Belgian attackers with links to ISIS in Syria carried out the deadliest violence in France in decades — and how many may still be on the run.