TAPACHULA, Mexico >> About 5,000 migrants from Central America, Venezuela, Cuba and Haiti set out on foot from Mexico’s southern border Monday, walking north toward the U.S.

The migrants complained that processing for refugee or exit visas takes too long at Mexico’s main migrant processing center in the city of Tapachula, near the Guatemalan border. Under Mexico’s overwhelmed migration system, people seeking such visas often wait for weeks or months, without being able to work.

The migrants formed a long line Monday along the highway, escorted at times by police. The police are usually there to prevent them from blocking the entire highway, and sometimes keep them from hitching rides.

Monday’s march was among the largest since June 2022. Migrant caravans in 2018 and 2019 drew far greater attention. But with as many as 10,000 migrants showing up at the U.S. border in recent weeks, Monday’s march is now just a drop in the bucket.

“We have been traveling for about three months, and we’re going to keep on going,” said Daniel González, from Venezuela. “In Tapachula, nobody helps us.”

Returning to Venezuela is not an option, he said, because the economic situation there is getting worse.

In the past, he said, Mexico’s tactic was largely to wait for the marchers to get tired, and then offer them rides back to their home countries or to smaller, alternative processing centers.

Irineo Mújica, one of the organizers of the march, said migrants are often forced to live on the streets in squalid conditions in Tapachula. He is demanding transit visas that would allow the migrants to cross Mexico and reach the U.S. border.

“We are trying to save lives with this kind of actions,” Mújica said. “They (authorities) have ignored the problem, and left the migrants stranded.”

The situation of Honduran migrant Leonel Olveras, 45, was typical of the marchers’ plight.

“They don’t give out papers here,” Olveras said of Tapachula. “They ask us to wait for months. It’s too long.”

Mújica later wrote in a message that the group had only made it about 9 miles (14 kilometers), and had stopped to spend the night in the town of Alvaro Obregon. He wrote the group planned to try and cover more distance in the coming days, but that the number of women and children had to be taken into account.

The southwestern border of the U.S. has struggled to cope with increasing numbers of migrants from South America who move quickly through the Darien Gap between Colombia and Panama before heading north. By September, 420,000 migrants, aided by Colombian smugglers, had passed through the gap in the year to date, Panamanian figures showed.