The Border Guard Service of the Russian Federal Security Service (FSB) has asked the Ukrainian side to provide information on two Russian servicemen who went missing in Ukraine, Ukrainian State Border Guard Service spokesman Oleh Slobodian told Interfax on Friday.

"The Russian border guards have asked us to provide information on their servicemen. Thus, they have formally confirmed that their servicemen have gone missing in Ukraine," he said.

Ukrainian border guards, acting together with other structures concerned, are currently taking filtration measures with regard to the detained persons and working to establish their identities, he said. A decision on transferring them to the relevant agencies will be made after these measures have been completed.

Ukrainian State Border Guard Service head Viktor Nazarenko said earlier that Kherson unit border guards and Ukrainian armed forces servicemen had detained two unknown persons without documents in the Kherson region overnight into June 30. Those detained were subsequently identified as servicemen of the Russian FSB's Border Guard Service.