can I erase /var/tmp?

[Susan G. Kleinmann]

I just noticed that my /var/tmp directory contains:
12784   base-tmp-6491
2       extract-tmp-10628
2       extract-tmp-10702
1       extract-tmp-6127
1       extract-tmp-6208
1       extract-tmp-6289
7676    partial-tmp-6491

What creates those directories, and can I erase them?

TIA,
Susan Kleinmann