Counterintelligence agency director Serhii Levchenko told a briefing, Censor.NET reports.
The group was headed and coordinated by a Ukrainian female citizen with pro-Russian views. Ukraine's counterintelligence says she had been trained in temporarily occupied Crimea and participated in the events of May 2, 2014 in Odesa.
She was ordered by her Moscow curators to organize pro-Russian movements and gather data on Ukraine Armed Forces units, including at the border areas.
SBU official Oleksandr Tkachuk said nine members of the ring have been detained. Four of them have been put under arrest, the rest are being controlled by the SBU.
The agencies have not specified whether all of the detainees are from Odesa. All of them have Ukrainian passports, but it is not yet known if they possess passports of other countries.
The aim of the ring was to penetrate into strategic and military facilities in Ukraine's south. They were supposed to gather information of Ukraine military units redeployment. In addition, the spy ring was to commit terrorist attacks and sabotage against Ukrainians in the south of the country, Tkachuk said.