several large files in Virtual Machines

I checked my disc space with OmniDiskSweeper today, and saw that the virtual machines takes up a huge chunk of my disc space (around 11 GB). Within Windows 7 x64.vmwarevm I find several files named Windows 7 x64-s followed by a three digit long number (s001 to s005 and s016). Each one of them is 2 GB large.

Are these duplicates? If so, are they safe to delete?

In my Finder window this appears as one large 12 GB file

Thanks!