Three people have been injured in the Belgian capital, Brussels, after a woman attacked them on a bus with a knife.

One of the victims was only slightly injured and other two are in a more serious condition, RTBF reports. The ‘unstable’ attacker is said to have been shot by police.

Belgium media quoted unnamed sources describing the women as suffering from “psychological disorders” and insisting it is not an act of “terrorism”.

The attacker survived the shooting and was arrested at the scene.

A security perimeter has been installed and the Brussels public prosecutor is already on location.

The Belgian capital has been on high alert since local Islamic State militants carried out the attacks in Paris last November and suicide bombings in Brussels itself in March.