Baku, November 21, AZERTAC
The subway system in Belgium's capital was shut down on Saturday as authorities declared a "serious and present threat" of terrorism.
The national emergency centre declared a Level 4 threat - the highest possible - overnight into Saturday, according to the news 24.
No details were released, other than to say the situation had received a "new assessment" in the wake of the Paris bombings.
A subway spokesperson said there would be no service all day, with no decision yet on whether to reopen for Sunday. Buses and trams did continue to provide service in Brussels.
Extra security was also reported at the nation's airports and train stations.