WARSAW, Poland (AP) — Poland’s prime minister on Friday expressed support for the army troops and the border guards protecting the frontier with Belarus from migration pressure after reports of shots — possibly blank ammunition — fired at Polish troops by Belarusian forces.

Premier Mateusz Morawiecki tweeted that “all state powers” were with the border guards and the military protecting the border.

“I am and I always will be firmly with our soldiers and our Border Guards," Morawiecki said on Twitter. “I want to thank our services for their professional and responsible approach.”

Earlier Friday, a spokesperson for Poland's Border Guards said Belarusian forces fired shots at Poland's troops across the European Union's eastern border Thursday. She didn't specify the forces.

Anna Michalska said no one was hurt and that most probably blank ammunition was used. She said the guards were under increasing pressure and stress as there was a growing number of incidents in which objects were being thrown at Poland's service members from the Belarus side.

In Belarus, State Border Guard Committee spokesperson Anton Bychkovsky rejected the claim of shots fired, saying that the Belarusian border guards hadn't used weapons over the last 24 hours, according to the Russian state news agency Tass.

Bychkovsky said that the committee has officially asked Polish authorities to specify their claim, Tass said.

EU members Poland, Lithuania and Latvia are guarding their borders against pressure of migrants from the Middle East and Africa, saying they are being organized and encouraged by the Moscow-backed Belarusian government, as an element of “hybrid war," seeking to destabilize the EU in retaliation for western sanctions on the authoritarian government in Minsk.

Follow AP’s global migration coverage at https://apnews.com/hub/migration