Both of our Internet Service Providers (main and backup) are experiencing problems, so the game servers (and Survival Forum) can be inaccessible for the next 12-18 hours.
The main one expected to be recovered not earlier than Feb 1st @ 6pm (Server Time / UTC+4).
The servers are online via our alternate ISP, but there are some problems with the link too.
Looks the problem is bigger than it we thought, so it's not possible to resolve in a short time.
We are keeping in touch with our ISPs in order to bring the links up as soon as possible.
Edit (2013-02-01 1:25pm Server Time):
Everything is back to normal operation.