Central American mothers lay pictures of their children who went missing while crossing Mexico for the United States on the steps of the Basilica de Guadalupe in Mexico City on Saturday. For the 10th year in a row, mothers and relatives of missing Central American migrants are caravanning through Mexico to demand answers on the fate of their children and to call for greater protection for transiting migrants. Tens of thousands of migrants have gone missing while passing through Mexico, where they are vulnerable to extortion and abuse – by both police and criminal gangs.