Little particles appearing on render When I render preview my animation little twinkling particles appear. 

I might have turned them on but since I'm new to Blender I don't know how to turn it off. 





@Jaspa I'm sure that cycles did finish rendering. In fact, this was just a preview of a render (if that changes anything?). I'm posting another screenshot of a different position of my animation and there's no little dots to see on buildings, except on the building from a first screenshot in the distance.
As Jaspa mentioned you should go to render tab, then go to sampling and increase the render samples to something like 1000 (the more the higher the image quality)
then hit render (this option is in the render tab)