text: Another user in the dark web - a hidden part of the internet where guns, drugs and child abuse images are traded - alerted police, a spokesperson said.
  The boy's body was subsequently found in the cellar of a house in Herne, North Rhine-Westphalia.
  Police say the 19-year-old suspect may be armed.
  Searches are being carried out in towns near Herne, which lies in the Ruhr area, a heavily industrialised region.
  Reports say the suspect, who is on the run, is a martial arts enthusiast.
target: A manhunt is under way in Germany after a man allegedly stabbed a nine-year-old neighbour to death and uploaded a video boasting of his deed to the dark web.