The kids bodies were discovered in an apartment building in Solingen.
Pictures show several police vehicles and ambulances parked outside the flat block.
Police confirmed the grim discovery this afternoon in a high-rise estate.
Solingen is a city of 160,000 people in western Germany between Dusseldorf, Cologne and Wuppertal.
Cops said they could not confirm who discovered the children.
Police did not release information on the cause of death or any suspects in the case.
The identity of the children remains unknown.