The raids, involving 400 police officers, were part of an investigation which began last year into a 28-year-old Russian of Chechen origin.
The raids, involving 400 police officers, were part of an investigation which began last year into a 28-year-old Russian of Chechen origin who is suspected of "preparing an act of violence against the state".
The suspect was believed to have been planning to join IS jihadists in Syria.
Police said no arrests were made Tuesday but that 10 other men and three women -- all Chechens aged between 21 and 31 all awaiting decisions on asylum requests -- were now under suspicion over their role in "terror financing".
Several of them were still being interrogated, said Holger Poppenhaeger, interior minister of the state of Thuringia.
The raids targeted 12 apartments and a shelter for asylum seekers in the eastern states of Thuringia and Saxony, Hamburg in the north, North Rhine-Westphalia in the west and Bavaria in the south.
Potential evidence including laptops, telecommunications equipment, hard-drives and bank statements were seized, said Poppenhaeger, adding that investigators were seeking to establish "if there is direct or indirect financing of the IS group".
Police said there was "no concrete danger of an attack".
Germany has so far been spared large-scale jihadist attacks.
But Europe's biggest economic power has been shaken by two assaults claimed by IS and carried out by asylum seekers -- an axe rampage on a train in Wuerzburg that injured five, and a suicide bombing in Ansbach in which 15 people were hurt.
Police said this month they had foiled an alleged plot by a Syrian refugee to bomb one of Berlin's airports.
Police said that there were no initial indications that those under investigation Tuesday had any links to those attacks, which have fuelled anxiety over Germany's record influx of nearly 900,000 asylum seekers in 2015.