Belarus on Monday accused Poland of firing warning shots and using tear gas and physical force to push back migrants trying to enter the European Union through their volatile border.Ties between Minsk and Warsaw, frozen for years, hit new lows after Belarus strongman Alexander Lukashenko allowed Russia to use his country to attack Ukraine, which Poland backs.The Belarusian border service said Polish guards routinely use "violence and abuse" to turn away refugees, including using tear gas and physical force."Recently, there have been several cases when Polish soldiers took foreigners to the fence on the border with Belarus and then forced them out through the animal wicket," a statement said.