EU and OSCE monitoring missions have been stationed in buffer zones adjacent to South Ossetia and another separatist republic, Abkhazia, since the withdrawal of Russian troops on October 8.
The measures are part of international efforts to stabilize the region following Georgia's invasion of South Ossetia on August 7, which triggered a five-day conflict with Russia.
Dmitry Medoyev said during a RIA Novosti video conference that there has been a surge in crime in the buffer zone near South Ossetia since Russian troops left the area.
"According to our information, 21 people have been abducted from the zone, which is supposed to be monitored by EU observers, since October 8, including children, women and elderly people," Medoyev said.
Only two of the abductees have been released for ransoms, he said. "Where were the European monitors?"
The official said the 200 EU monitors working in the buffer zone are incapable of controlling the territory extending for 140 kilometers along the South Ossetian-Georgian border.
Russia recognized South Ossetia and Abkhazia as independent states on August 26, two weeks after the end of the conflict.
The two republics broke away from Georgia following the collapse of the Soviet Union in the early 1990s, amid armed conflicts that claimed thousands of lives.
