noise – Very noisy image, looks like stars

Yesterday I did some long exposure shots, and it turned out to go quite well (in my opionion), just one issue is that the image is very noisy like I’ve never seen before. The noise looks like stars, and in the sky it looks okay. However stars on the groud is ugly.

Any tips for fixing this? Shot in 1600 ISO (max on my camera).
Image size is decreased to fit into Stackexchange, hopefully they are still visable Noise image