Belgian police have launched a manhunt for a teenager after footage emerged of him calling for “the murder of all Christians”.

The video shows the 15-year-old, who has not been named, in Verviers and, in Arabic, declaring, “Oh Allah, destroy the odious Christians. Oh Allah kill them all.”

The boy is filmed on a French website saying, “Don’t spare any of them.”

The film was shot in Verviers, the scene of a successful anti-terrorism operation last year.

Police said the boy has been identified and is on a list of radicalised persons, but did not disclose his name.

 A source said the teenager, the son of a local radical imam, posed a potentially « serious threat » to the public and they wanted to trace him « as soon as possible. »

Verviers Mayor Muriel Targnion said the video was being taken seriously and has asked the police to trace the boy “as a matter of urgency.”