With Mexico unable to stop a caravan headed to the U.S. from Guatemala, the group is burgeoning in size.

The original 2,000 Central Americans either swam or rafted across a river separating Guatemala and Mexico Saturday, with estimates of 3,000 more joining them as they head to the U.S. in time for next month’s election.

Sunday the group paused at the Mexican town of Tapachula, occupying a mile-long column about 10 abreast.

It is unknown from where the additional 3,000 came – Guatemala or Mexico. There are still another 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.

Maria Teresa Orellana, a resident of the neighborhood of Lorenzo handed out free sandals to the migrants as they passed. “It’s solidarity,” she said. “They’re our brothers.”

Olivin Castellanos, 58, a truck driver and mason from Villanueva, Honduras, said he took a raft across the river after Mexico blocked the bridge. “No one will stop us, only God,” he said. “We knocked down the door and we continue walking.” He wants to reach the U.S. to work. “I can do this,” he said, pointing to the asphalt under his feet. “I’ve made highways.”

The migrants, who said they gave up trying to enter Mexico legally because the asylum application process was too slow, gathered Saturday at a park in the border city of Ciudad Hidalgo. They 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 capped a day in which Mexican authorities again refused mass entry to migrants on the bridge, instead accepting small groups for asylum processing and giving out 45-day visitor permits to some. Authorities handed out numbers for people to be processed in a strategy seen before at U.S. border posts when dealing with large numbers of migrants.

But many became impatient and circumventing the border gate, crossing the river on rafts, by swimming or by wading in full view of the hundreds of Mexican police manning the blockade on the bridge. Some paid locals the equivalent of $1.25 to ferry them across the muddy waters. They were not detained on reaching the Mexican bank.

Migrants cited widespread poverty and gang violence, one of the world’s deadliest nations by homicide rate, as their reasons for joining the caravan.

President Trump last week warned Mexico that “we’re calling up the military – not the Guard” if the government cannot stop the caravan from reaching the border.

“They’re not coming into this country,” he said.