The BBC’s Giles Tremlett in Warsaw
Poland’s border guards fired water cannon at dozens of migrants trying to breach the frontier with Belarus, in the latest violence across Europe.
Last month, two migrants died after clashes at the Polish-Hungarian border, while the Bulgarian authorities detained 22 migrants trying to cross from Turkey.
One of the migrants died on Sunday of the hand and one died of wounds he had suffered at the border in June.
Reporting from the Polish border with Belarus, BBC News’ Giles Tremlett said the border was packed with police officers and vans full of officers and special forces.
The migrants’ numbers had noticeably increased since June, and by 9am local time on Wednesday about 150 had gathered, says Mr Tremlett.
The migrants threw rocks at police, while some jumped or rolled on to the highway.
The Polish government says up to 300 migrants may attempt to cross the border in coming days, and says anyone caught will be sent back to Belarussian officials.
Poland’s Interior Minister Joachim Brudzinski had said in June that migrants should avoid trying to cross the border, saying they faced “inhumane treatment” and that they would probably “return quickly to the (transit) countries”.
On Wednesday morning the Polish border guards fired water cannon at the migrants, and shot pellets and tear gas.
The migrants were then encouraged to leave Poland and say they would meet the second night in Belarus.