CIUDAD HIDALGO, Mexico (CBSNEWS/AP) — 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.

Their numbers swelled to about 5,000 overnight and at first light they set out walking toward the Mexican town of Tapachula, 10 abreast in a line stretching approximately a mile.

gettyimages 1052697726 e1540154665953 Migrant Caravan Swells To 5,000 In Mexico, With Members Vowing To Reach US

Honduran migrants take part in a caravan heading to the US, on the road linking Ciudad Hidalgo and Tapachula, Chiapas state, Mexico, on October 21, 2018. (PEDRO PARDO/AFP/Getty Images)

It was not immediately clear where the additional travelers had materialized from since about 2,000 gathered on the Mexican side Saturday night. They seemed likely to be people who had been waiting on the bridge over the Suchiate River or in the Guatemalan town of Tecun Uman and who decided to cross during the night.

President Trump repeated his recent threats to seal the border to prevent the migrants from entering the U.S. in a series of tweets Sunday afternoon, blaming Democrats for the situation. “Full efforts are being made to stop the onslaught of illegal aliens from crossing our Souther [sic] Border … The Caravans are a disgrace to the Democrat Party. Change the immigration laws NOW!”

At dawn there were still an estimated 1,500 migrants on the Guatemalan side hoping to enter legally.

They marched on through Mexico like a rag tag army of the poor, shouting triumphantly slogans like “Si se pudo!” or “Yes, we could!”

As they passed through Mexican villages on the outskirts of Ciudad Hidalgo, they drew applause, cheers and donations of food and clothing from Mexicans.

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