Immigration agents lined a highway in southern Mexico offering hundreds of migrants temporary residency if they abandoned their march. Exhausted, some accepted, while others kept going, afraid of being deported.
The offer of residency cards has split opinion and sowed suspicion within the caravan that set out three weeks ago from near the border with Guatemala to demand refugee status.
Promises of food, water and an airconditioned bus to take them to a shelter while awaiting a one-year permit on humanitarian grounds were enough to persuade several migrants.
But many others were unconvinced, despite suggestions that the card could smooth their passage to the United States.
"Lies -- they're going to deport us!" men and women shouted angrily at the dusty checkpoint in the southeastern state of Veracruz, where immigration agents worked hard to try to persuade them to stop marching.
Elena Raudales, a migrant from Honduras, showed AFP a document called a "visitor's card for humanitarian reasons" with her name and photograph that she was given earlier this year.
"Even so they detained me two months ago and sent me back" to near the border with Guatemala, she said.
"We're not going to believe anything anymore," she added.
According to officials, around 1,500 people have accepted the temporary residency offer, reducing the caravan's size considerably since it left the southern city of Tapachula on October 23.
Around 800 people remain in the group, mostly Central Americans fleeing violence and poverty.
- 'Lied to us' -
Many migrants are reluctant to accept the residency offer because they fear being tricked and deported, said Christian Joel, a 22-year-old Honduran.
"They lied to us already," he said, complaining of a lack of assistance from the immigration authorities since he arrived in Mexico a year ago.
He is making a second attempt to return to the United States, where he lived for 18 years from the age of two with his family until he was deported for driving without a license, he said.
But some other migrants went willingly with the authorities in the hope of getting legal documents.
"We're going to try.... We've already come a long way and we're very tired," said 30-year-old Salvadoran Walter Ceron as he prepared to board a waiting bus.
The offer was also tempting for Vilma Escobar, 26, who was getting ready for another day pushing her two-year-old son's stroller along the highway under the beating sun.
Sometimes she thinks "I would like that card, but it means taking a risk," said the 26-year-old Guatemalan, unsure if going with immigration would take her closer or further from her goal of reaching the United States.
- 'No legal value' -
US President Joe Biden's arrival in the White House has led to increased flows of undocumented foreigners arriving in Mexico hoping to be allowed into the United States.
More than 190,000 irregular migrants were detected by Mexican authorities between January and September this year, three times more than in 2020.
Some 74,300 have been deported.
The United States meanwhile registered more than 1.7 million people entering illegally from Mexico in the year to September, a new record.
Mexican officials have said they will not stop the migrant caravan as long as the migrants travel on foot, while also trying to persuade them to give up.
Irineo Mujica, a Mexican activist accompanying the caravan, is also skeptical about the cards being offered to the migrants.
In reality they "have no legal value" and cannot be used to travel freely or find a job, he said.
The aim is "not to help migrants, but to dissolve the caravan," added Mujica, 50, who emigrated to the United States as a child and has dual citizenship.
He shrugs off criticism from the Mexican government as well as suggestions from the US ambassador to Mexico that his actions have enriched people smugglers and criminals.
"It doesn't bother me because I'm not a politician," Mujica said.
"I have a moral responsibility, nothing more," he added.