By Hajer M'tiri
Belgian police locked down a part of a suburb
A large number of police, backed by a helicopter, had been deployed in the municipality of Forest in the Brussels-Capital Region, according to Belgian broadcaster RTL.
The broadcaster quoted Forest Mayor Marc-Jean Ghyssels as saying police "suspect the presence of an armed man or men."
Some local media also said police were responding to reports of a murder.
Police so far has not made any official comment yet on the operation.