The number of migrants, says Mexico, has dropped to about 4,500 from more than 7,200. Nearly 1,700 migrants remained in Mexico to seek asylum.
Author: David Agren, Special to USA TODAY
Caravan migrants flood southern Mexico, tugging suitcases and hopes of reaching U.S.-Mexico border
In southern Mexico, families of Central American migrants tugged suitcases and pushed baby strollers as they made their way northward to US border.