A spokesman for Poland's special services, Stanislaw Zaryn, said Belarusian security personnel were "firing empty shots into the air, simulating dangerous events", while also providing tools to the migrants to help them destroy the border fence.
Reuters was not able to verify the source of the shots.
On Tuesday (November 9), the EU accused Belarusian President Alexander Lukashenko of using "gangster-style" tactics in the months-long border standoff, in which at least seven migrants have died.
Polish private radio RMF said around 200 people had tried to breach the border on Tuesday afternoon, and a second group of around 60 people had tried after midnight.
Polish police said all those who tried to cross were detained, and that the force of Polish soldiers stationed at the border had been strengthened to 15,000 from 12,000.