Austrian environmentalists warned the governments in Vienna and Prague that they will block all 16 border crossings with the Czech Republic the Austrian government files a complaint with an international court over the Czech nuclear power plant in Temelin by next month, the activists said during a protest outside the plant.

The opponents of the Czech NPP also said they mull options to extend the duration of the blockades to up to a day.

On May 11, the activists stopped the work of 12 border crossings for two hours, the biggest protest in seven years.

"We will block all 16 border crossings as long as our demand is granted," Roland Egger, an organiser of the protests, told journalists.

However, Austrian Chancellor Alfred Gusenbauer said the government does not intend to file a lawsuit against Prague over Temelin.

Instead, he said Vienna will urge Prague to stick to the Melk agreement which describes all security measures to be taken in Temelin.