The terror cell that was raided by Belgian police in the eastern town of Verviers is most likely linked to the Isis [Islamic State] group, according to a senior Belgian counterterrorism official.

The official, speaking on condition of anonymity, told CNN that members of the terror cell had travelled to Syria.

They were allegedly given instructions by IS members to conduct attacks in Europe in response to the US-led coalition's air strikes against the group's positions in Syria and Iraq.

Following the terror raid, in which two members were killed and one arrested, Belgium raised its security alert to its second-highest level.

Amid reports that the cell was just hours away from launching an attack, Belgian officials could not confirm if there was any link between the cell and the deadly attacks in Paris last week that saw 17 people killed.

The Jewish community in Belgium had decided to close schools in the cities of Brussels and Antwerp as they were told that they could have been potential targets for the cell's attack.

Local residents reported gunfire and explosions in the terror raid, with "machine guns were firing for about 10 minutes".

Another witness said that he witnessed two young men of North African descent "dressed all in black carrying a bag of the same colour."