PIJIJIAPAN, Mexico (AP) — Central American migrants hoping to reach the U.S. now carry the added anxiety of the pursued after Mexican police and immigration agents detained hundreds in a surprise raid on a caravan in Mexico's south.

While their compatriots were been taken into custody Monday, hundreds of other migrants scrambled away into the brush along the highway in Chiapas state to elude authorities.

Many had already learned they would not be received in towns with the same hospitality that greeted previous caravans, and now they know they won't be safe walking along the rural highway either. Mexican authorities detained hundreds in the largest single raid on a migrant caravan since the groups started moving through the country last year.