In the primeval forests of Poland, haunting traces of people unseen.

A Belavia airline boarding pass from Dubai to Minsk left under a birch tree. A child’s overalls abandoned next to the old rail track, linking Belarus with Poland. An eye shadow palette hidden among brown, damp leaves.

These are not regular sights in the Bialowieza Forest, one of the last remaining swathes of a primordial forest that used to stretch across Europe, home to bison and deers. The people who come across them are not regular hikers, either. They are residents and activists looking for asylum seekers from the Middle East, victims of a standoff between a Belarusian government trying to funnel them into Poland, and a Polish government, supported by the European Union, adamant at keeping them out.

“We used to come to the forest in search of the beauty of nature,” said Iza, a local resident who has been helping asylum seekers, and who asked to be identified only by her first name for fear of repercussions from authorities and far-right groups. “Now we are looking for things that seem out of place.”

In the face of a growing humanitarian crisis and a near-total absence of state support, locals have stepped in, providing migrants with food, water, warm clothes and power banks. They relentlessly patrol the forest, looking for people in need.

“In the beginning, I could not even look into their eyes,” said Maciej Jaworski, who lives close to the border in what is known as the exclusion zone, which the Polish authorities designate as off-limits for nonresidents. “I can give them food and water, talk to them. If they don’t need medical help, this is pretty much it.”

Sometimes they spot migrants, shivering under ancient trees, starving and desperate. But more often they find objects: haunting traces of people that passed through and disappeared. Some seem to have been abandoned in haste. A backpack filled with documents written in Arabic, one page carefully folded into a green-and-red jewelry box. Warm shoes scattered at the edge of the forest.

“This probably means they were running from border guards,” said Iza’s husband, who asked to be identified only as Roman. “If they were rushing to get into a smuggler’s car, they would have taken the documents with them.” Since the beginning of the crisis, many asylum seekers have been summarily pushed back into Belarus by Polish guards.

A mass of empty backpacks, sleeping bags and waterproof jackets abandoned in a meadow, where the forest transforms into vast fields, betray the location of a pickup spot for smugglers, who drive some of the asylum seekers who make it through the forest farther west, toward Germany.

Some objects hang on trees — like a pair of ski pants, carefully folded on a branch, lying under an empty tuna can with a Belarusian label. Perhaps that person had made it out of the forest. Iza recognized the pants as part of a rescue package that she had hung on a tree a few days earlier. “We will now give them to someone else,” she said. “Winter is coming.”