Hundreds of migrants are stranded in the cold on the border between Belarus and Poland, caught up in a geopolitical standoff on Europe’s eastern edge.

The European Union, like Poland and the U.S. State Department, accuses Belarus of sending throngs of people to the border to pressure its neighbors, a claim the country denies. But in the frigid forests between the two countries, rising numbers of refugees have been camped out for days, and aid workers warn they need help.