A caravan of thousands of Central American migrants is speeding its journey to the US border, breaking up into smaller groups as buses and trucks carry some hundreds of miles in a day, while others behind remain stranded.
Authorities have been struggling to deal with the first sizeable group of 357 migrants who arrived in the border city of Tijuana aboard nine buses.
Tijuana's head of migrant services says the group arrived on Tuesday and immediately went to a stretch of border fence to celebrate.
Cesar Palencia Chavez says authorities had offered to take the migrants to shelters immediately, but they initially refused, saying they wanted to stay together.
But he says that after their visit to the border, most were taken to shelters in groups of 30 or 40.