
Manth is held in West Germany after three bodies were found in the apartment building in Whitefeld, in the area of Westerwald.
The suspect escaped from the scene when officers arrived and escaped, a police spokesman told the German press agency.
Police advise residents in the vicinity to stay home and warn people not to take hitchhops, local media reported.
Details of the killed were not released.
The German exit BILD reports that a special working group is on the spot and There is a police helicopter.
The city is completely fenced and the vehicles enter and leave are checked.
A police spokesman told Bild that the emergency call was at 3:45 local time (2.45 pm BST).
Local media reported that police said the incident happened in a family home and the three victims include two men and one woman.
Weitefeld is home to about 2,200 people.