pf block IP immediately

[skeletor at lissyara.su]

Hello.
I have a FreeBSD 9.2 amd64 with pf (build in kernel).
Can pf block some IP (sessions) immediately? Next rule can block only 
new sessions, but currect open sessions stay open as long as they open by IP

block quick from X.X.X.X to any
block quick from any to X.X.X.X

Also, I can do pfctl -F sessions, but it flushes all sessions of all users.

tcpdrop not shown this sessions, because this is a nat sessions.

Thanks.