About 300 migrants walked out of a southern Mexican city Wednesday, hoping to move north, even as the activist who helped organize them remained in police custody over allegations of human trafficking.

Heyman Vázquez, a Catholic priest, accompanying the migrants said the arrest Tuesday in Tapachula of the leader of a local nongovernmental organization Luis García Villagrán was "unjust.”

Mexico President Claudia Sheinbaum said during her daily news briefing Wednesday Villagrán is not an activist.

She said there had been an arrest order pending for García Villagrán for years adding he was tied to trafficking people, and "that is the crime.”

It was unknown why the outspoken and very public figure hadn’t been arrested earlier.

The group of migrants that left Tapachula, near the border with Guatemala, earlier Wednesday was small in comparison to migrant caravans in years past.

There has been very little movement of migrants in public since U.S. President Donald Trump took office in January, though migration numbers had been falling even prior to that.

Those walking Wednesday said their goal was not reaching the United States, but rather central Mexico.

They complained that they had been waiting for months to legalize their status or receive asylum.

"There are people who have been waiting here for a year and six months like me,” said Juan Pablo Urrutia from Nicaragua.

In recent years, the Mexican government has worked to contain migrants in southern Mexico — far from the border with the United States

At times, this strategy has swollen migrant numbers in Tapachula until hundreds set out walking in protest. Chiapas is Mexico’s poorest state and migrants complain there is little work or available housing.

The migrants were escorted by immigration agents, police, marines and paramedics.

AP video by Raúl Mendoza