Polish border with Belarus has turned into a battlefield as the country struggles to push back the migrants who are desperately trying to cross into Poland. There were clashes between Polish forces and several thousand migrants on the Belarus side who tried to breach the border fences. The crisis are rooted in the re-election of Russia-backed Belarus president Alexander Lukashenko last year that triggered protests in his country. Lukashenko met the protesters with force, prompting European Union to impose sanctions. To know how the crisis unfolded and what is the current status, watch this explainer.