SUKRUPASA, Turkey — The small squat structure, a cross between a kiosk and a duck blind, was starkly pale against the brown, soggy hillside a few hundred yards away.

“Bulgarian border police,” said Hasan Bulgur, 73, pointing as he leaned on a crooked walking stick at the edge of this village in northern Turkey. “They are watching us now. When the refugees try to cross, they are stopping them and pushing them back, sometimes beating them, robbing them, even unleashing dogs on them.”

Groups of migrants, having failed to make it past the Bulgarians, frequently straggle out of the fields here, sopping wet after fording a nearby river. They arrive sometimes in groups of as many as 50, some of them with bruised skulls and bashed noses, Mr. Bulgur and other residents said.

“They hit me and took my money,” said Alan Murad, a 17-year-old Iraqi asylum-seeker living at a refugee center in Sofia, Bulgaria’s capital, recounting his treatment by the Bulgarian border authorities. “I ran away from hell at home, trying to find paradise in Europe. Instead, I found another hell.”