SSG-140, Route based VPN: How to deny incoming IKE form specific IP ?

Hi Community,

My SSG-140 each 10 seconds has receiving IKE packets (Initial Phase 1 packet) from an unrecognized peer gateway, I see in the event log its source IP. 

I've tried to implement deny policy from Untrust to Untrust, from Untrust to Global zone, but no success.

Is there any way to deny all incoming traffic from this specific IP?

Thank you in advance,

Dmitry.