problem removing directory

[Alex de Kruijff]

Hi,

I wanted to move /var/tmp to /tmp and symlink it for security reasons.
I move /var/tmp to /var/tmp-old and copied the files to /tmp and them 
symlink /var/tmp to /tmp. So far so good.

However, now i am unable to remove one directory and need some help in
removing this.

Intranet# ll
total 1
dr-xr-xr-x  2 root  wheel  512 Mar 16 22:04 empty/
Intranet# pwd
/var/tmp-old/temproot/var
Intranet# ll
total 1
dr-xr-xr-x  2 root  wheel  512 Mar 16 22:04 empty/
Intranet# rm -rf *
rm: empty: Operation not permitted
Intranet# mv empty /tmp/
mv: empty: Operation not permitted
mv: /bin/rm: terminated with 1 (non-zero) status: Cross-device link

Tanks for any help in advance,
Alex