possible intrusion?

[Sergei Vyshenski]

Today discovered the following in /var/log:

-rw-r--r--  1 root  wheel    176 Jul  1 14:37 wtmp
-rw-r--r--  1 root  wheel      0 Jul  1 05:20 wtmp.0
-rw-r--r--  1 root  wheel      0 Jul  1 05:00 wtmp.1
-rw-r--r--  1 root  wheel  20460 Jul  1 00:19 wtmp.2
-rw-r--r--  1 root  wheel      0 Jun  1 05:20 wtmp.3

While file /etc/newsyslog says:

/var/log/wtmp           root.wheel      644  3     *    @01T05 B

The system is 4.8-STABLE FreeBSD 4.8-STABLE #0: Tue Jun 17 22:09:23 MSD 2003

Could this mean the sign of intrusion?

Thank you very much for any comment ahead of time,
Sergei