"We conducted a multi-stage special operation to defang the network overseen by Russian special services. It worked in eastern and southern regions of Ukraine. According to our intel, Russia's Military Main Intelligence Directorate [also known as GRU] was involved," SBU department chief Oleksandr Tkachuk said at a briefing on Wednesday. He said the saboteur group was made up of acting and former Ukrainian military personnel, who received instructions to infiltrate critical infrastructure facilities in southern Ukraine and collect data. They also planned to spy on military facilities. The group also planned to prepare and conduct diversions against Ukrainian citizens in southern Ukraine. Tkachuk said all members of the group have Ukrainian passports. Four of the nine have been remanded to pre-trial custody. The remaining five are confessing to Ukrainian investigators. A criminal case has been opened on state treason and illegal possession of arms.