Around 200 Ukrainians blocked a road to a border crossing into Poland on Wednesday.
"We have received information from people who still managed to cross the border that about 200 Ukrainians were blocking ... the road to the Korczowa crossing," a spokesman for Poland's border guard service said. "Some information suggests that they are opposition protesters."
The blockage was reported inside Ukrainian territory, near the crossing over the border to the Polish village of Korczowa.