CIUDAD HIDALGO, Mexico (AP) — The Latest on the caravan of Central American migrants hoping to reach the United States (all times local):

7:40 a.m.

A migrant caravan whose numbers swelled overnight to an estimated 5,000 people at the Mexico-Guatemala border has resumed its march toward the U.S. frontier.

The migrants had grown frustrated with Mexico's attempts to process them and circumvented authorities by crossing the Suchiate river illegally.

They have begun walking out of the border city of Ciudad Hidalgo at first light Sunday morning, headed 10 abreast for their next stop: the city of Tapachula.

It's not immediately clear where the additional travelers materialized from.

But during a caravan last spring, many migrants who had been working and living at the Guatemala-Mexico border decided to join the caravan when it passed because it was safer to travel together.

5 a.m.

Despite Mexican efforts to stop them at the border, about 2,000 Central American migrants swam or rafted across a river separating that country from Guatemala, re-formed their mass caravan in Mexico and vowed to resume their journey toward the United States.

The migrants say they gave up trying to enter Mexico legally because the asylum application process was too slow. They gathered Saturday at a park in the border city of Ciudad Hidalgo and voted by a show of hands to continue north en masse, then marched to the bridge crossing the Suchiate River and urged those still on it to come join them.

The decision to re-form the migrant caravan Saturday capped a day in which Mexican authorities again refused mass entry to migrants on the bridge. Instead they accepted small groups for asylum processing and giving out 45-day visitor permits to some.