Nikolai Baranov, an aide to the commander of the Joint Peacekeeping Force, said Georgian police seized the trucks late on 13 February.
Aleko Sukhitashvili, the chief of the Georgian military police, said the vehicles were impounded because their papers were not in order.
South Ossetia broke away from Georgia after a war in the early 1990s. The Joint Peacekeeping Force that helps patrol the region includes also Georgians and Ossetians.
Georgian Defense Minister Irakly Okruashvili said today that Tbilisi has a peace plan to bring South Ossetia back under its control next year.
The Georgian parliament is scheduled to vote on 15 February on whether to call on Russian forces to pull out of South Ossetia.
(civil.ge, primenews.ge, Interfax, AP)