Protesting against the operation of the Czech nuclear power plant Temelin, Austrian environmentalists blocked the main Austrian-Czech border crossing.
The plant is located some 60 km from Austria.
Two border crossings - Wullowitz/Dolni Dvoriste and Weigetschlag/Studanky - were blocked for one hour.
Austria and the Czech Republic have a long dispute over the safety of the Temelin NPP.
The Austrians insist Prague is not sticking to the Melk agreement under which the plants safety must be upgraded.
The organiser of the protest is Atomstopp association.