"The OSCE SMM can confirm that one of its local staff members in Luhansk region was temporary out of reach while being on leave. His whereabouts is currently known to the mission and he is safe. There are no further details available at this moment," the SMM wrote on its Facebook page on Monday. The Ukrainian Security Service (SBU) has not yet commented on a statement from the Russian Federal Security Service (FSB). The FSB earlier announced the arrest in Russia of an alleged SBU agent who worked as translator for the SMM in Ukraine and allegedly gathered intelligence for the Ukrainian secret services.