The crisis has led the EU to prepare further sanctions against Belarus, which it accuses of attempting to destabilise the bloc by pushing migrants across the border illegally.
Footage shared by a Polish government spokesperson and the Ministry of Defence showed a further escalation of the crisis at the border, where migrants have assembled in growing numbers on the Belarusian side in the last week, according to Reuters.
"Attention, attention, if you don't follow orders, force will be used against you," said a loudspeaker message directed at migrants throwing objects, according to the images that were shown on public broadcaster TVP.
Migrants threw bottles and wooden logs at Polish soldiers, and used sticks to try to break through the fence, the video showed.
The Interior Ministry said a policeman was seriously injured by an object thrown across the border and was in hospital with a suspected fractured skull.
The Polish defence ministry said in a tweet that Belarusian authorities had given migrants sound grenades to throw at Polish soldiers and border guards.
The EU says Belarus is encouraging migrants to cross the border in revenge for earlier sanctions over a crackdown on protests last year against President Alexander Lukashenko's re-election.
