Safe to delete /var/root/vartmp?

I'm having a low diskspace warning on an EX4200. I think I've found the culprit in /var/root/vartmp, which is 104MB.

My question is, is this safe to delete? Some quick Googling didn't give me any idea of what it does. There also a 3.3KB file in /var/root called "et a".

Neither of these two files are present on the other members.