Special police forces have been searching the apartment of a 27-year-old man arrested on Wednesday over a suspected bomb plot in Eisenhüttenstadt, Brandenburg.
Investigators said that they discovered “only small amounts of pyrotechnic products” and that “there is also evidence of a possible closeness to Isis”.
But police said that they did not find evidence of a planned attack and that the man seemed “not mentally stable”.
The man is reportedly a German citizen and witnesses said that he “had converted to Islam”.
A police chief told Bild tabloid newspaper that officers had found seven posters with Isis symbols, an airsoft Kalashnikov gun, a camouflage suit, a protective vest, a gas mask, 37 “partly banned” firecrackers with black powder and cannabis.
But a concrete connection to Isis has not been found.
Brandenburg's Minister President Dietmar Woidke had said previously that the arrest had been made over a suspected “planned terrorist act” with a possible Islamist background, but the investigation would clarify the situation.
Prior reports that the man had been planning an attack aimed at a town festival at the end of August could also not be confirmed.