Mexican authorities have begun cracking down on the caravans of Central Americans journeying through the country toward the U.S. border. Mexican immigration agents and police detained en masse a migrant group of 371 people last week, the largest single raid on a caravan since migrants last year began making the trek north in large groups for safety. “They waited until we were resting and fell upon us, grabbing children and women,” said Arturo Hernández, 59, who fled into the nearby woods with his grandson. The roundup signals a reversal of Mexico’s previous tolerance of the caravans. Meanwhile, more than 1,300 mostly Cuban migrants escaped an immigration detention center in southern Mexico last week, and 600 of them are still at large. The migrants said the center, which held twice as many detainees as it was built for, was far too crowded and lacked sufficient bathrooms.