NOGALES, Mexico — The government of the largest city along the Arizona-Mexico border is taking control of the list of roughly 680 migrant families who are waiting in this border city to seek asylum in the United States.

In doing so, the city has become the first government along the border to get directly involved in the process by which migrants are able present their claims before U.S. officials.

Up until now, nonprofits in this border city — located across from its twin city of Nogales, Arizona — managed the list. In other border cities, such as San Luis Rio Colorado, across from Yuma, the migrants themselves keep track and pass the list on from family to family as the line advances.

The change in Nogales comes amid uncertainty over the future of these families as the administration of President Donald Trump implements restrictions on asylum that could effectively leave many of them stranded in Mexico.

On Sept. 12, the municipal government of Nogales, Sonora, took over the administration of the list, and tasked its Protección Civil, the office of emergency first responders, with managing it.

"We're seeing an increase in migrants arriving to Nogales, so logically it's for security reasons, both for the residents and for those who are arriving," said Pablo Dominguez, the director of Protección Civil in Nogales.

Despite the asylum crackdown by the Trump administration, Dominguez said an average of 200 names are added to the asylum list each month in Nogales. There are currently more than 680 families waiting in that city for their numbers to be called.

The increase, he added, has been mainly driven by the arrival of large numbers of Mexican families fleeing cartel-related violence in the country's impoverished southern states.

There also were rumors among migrants that spots on the list were being sold, or that people could pay to get ahead in the line, but Mexican authorities said no such complaints were confirmed or reported.

The change in who manages the list raised questions from nonprofit organizations in Nogales who regularly work with potential asylum seekers.

They question how committed the city government will be to ensuring the process runs smoothly and quickly, especially because space to process migrants at the port can open up at any time, including nights or weekends, and not just during business hours.

"In my view, the way it was managed before worked well," Renan Torres said. "But those were changes where they didn't take us into account. If they had, I would've voted for them to keep the way it was before."

Torres is the director of La Roca, a shelter housing nearly 20 migrant families across the street from the steel bollards that mark the border.

Since the mass arrival of families last April, nonprofits maintained a list to keep tabs on which migrant families were arriving and their place in line.

At first, the families would wait and camp out at the port of entry. The nonprofits devised a system to house migrants in shelters such as La Roca while they wait for their numbers to be called. The current wait time is nearly six weeks, according to shelter directors.

Brenda Nieblas helps run a shelter in Nogales and managed the list of asylum seekers before the city took over. She created groups on Facebook and the messaging app Whatsapp to keep migrants updated on the processing of families. She did not respond to The Arizona Republic's request for comment on this story.

Dominguez said that when the city took control of the list from Nieblas, they created a new messaging group to keep the families updated.

Denise Hernández Almendarez, 39, and her 8-year-old daughter were among the first migrants to test out the new system. Her number was called earlier this week after waiting more than a month in Nogales.

Before her number was called, she told The Republic that she had been spending a lot of time thinking about what U.S. officials would ask her.

"I feel a bit nervous, because you hear so many things. And even if you don't believe them all, you still can't help but feeling nervous," Hernández Almendarez said.

She would tell them she left Honduras in June, leaving two older children, because of gang violence and the "war tax" — extortion — they would attempt to collect from her.

"My daughter would go to school sometimes only twice a week or there were weeks where there were no classes. And to see so much death," she added.

She may be among the final Central American families who are allowed to claim asylum, at least for the time being.

Earlier this month, the Supreme Court allowed the Trump administration to move forward with restrictions that would bar mostly Central American migrants from seeking asylum in the U.S. if they did not first seek protection through one of the other countries they traveled through earlier.

Hernández Almendarez, for example, said she didn't apply for asylum in Guatemala or Mexico before reaching the U.S. border.

Acting Homeland Security Secretary Kevin McAleenan announced earlier this week that his department would end the practice of releasing asylum-seeking families to their sponsors in the interior of the United States.

Starting next week, the Homeland Security chief said they would instead be sent to Mexico to await the outcome of their asylum proceedings under the Migrant Protection Protocols, or deported to Central America if they did not express a fear of return.

Unlike other large border cities such as Tijuana or Ciudad Juarez, the Migrant Protection Protocols, or MPP, have not been implemented in Nogales or any of the other cities along the Arizona border.

It remains unclear whether the policy will be expanded to the Arizona border, or whether Central American families such as Hernández Almendarez's will be transported to other border cities that have the policy in place.

Have any news tips or story ideas about the U.S.-Mexico border? Reach the reporter at rafael.carranza@arizonarepublic.com, or follow him on Twitter @RafaelCarranza.

Support local journalism. Subscribe to azcentral.com today.