A small amount of flammable material was found Monday near military vehicles at barracks in Belgium, the defence ministry said, amid heightened tensions after the deadly Paris attacks that were co-authored by Belgian-born militants.
The ministry said there had been a "violation" at Heverlee military barracks near Leuven east of Brussels.
"The outer perimeter of the barracks was damaged... During the search of the area that followed, a small quantity of flammable material and a black bag were found near several military vehicles. No explosive material was found," it added.
Police, firefighters, emergency services and bomb disposal experts were deployed and some buildings evacuated. A probe has been opened, though life in the area quickly returned to normal, the ministry said.
Belgium is on its second highest terror alert, level three, after the November 13 Paris attacks left 130 people dead and French investigators linked several of the extremists behind the atrocity to Brussels.