The Intercept witnessed such a scene on June 4 in El Paso, Texas. At 6 a.m., the sun rose on a 15-year-old Guatemalan boy and his father who were trying to walk across the border to apply for asylum. They did not swim the Rio Grande or otherwise attempt to enter the country illegally — they’d made their attempt on an arcing, international bridge that joins El Paso with its Mexican sister city, Ciudad Juárez.

Even so, the practice of turning immigrants away has suddenly become routine, creating chilling scenes of immigrants and children camped out near the bridges, exposed to sun, wind, and rain, amid make-do bedding, scattered clothing, and trash. A few times a day, the immigrants walk to the middle of the bridges and ask to be admitted to the port of entry building on the U.S. side so that they can request asylum. They are almost always turned back.

U.S. Customs and Border Protection agents are systematically violating U.S. and international law by blocking immigrants at international ports of entry on the southern border from entering the country so they can claim asylum. Immigration civil rights advocates have been documenting this illegal behavior since late 2016, from Texas to California. It was sporadic then, and appears to have been based at least in part on CBP’s difficulties with handling large numbers of people.

I knew they were Guatemalans because I’d spoken with the man two days earlier. I spotted him and the group squatting disconsolately on the Mexican side of the bridge by the public bathrooms. This man and others in the group told me then that they were asylum-seekers afraid to go back to their home country because of violence there. They were extremely frustrated about being turned away. They recounted that the agents always told them there was “no room” to process them at the port of entry, and they should come back later when there might be room. There never was room. “False words,” the man with the son said, in Spanish that was heavily accented by Q’eqchi’, his indigenous tongue. Another man started crying.

They were stopped at the top of the bridge by two CBP agents who refused to let them cross, pointed them back to Mexico, and said to try crossing later. This was the sixth time in three days that the man, his son, and about a dozen other Guatemalans had been thus rejected.

#asylum @CBP #ElPaso #Guatemalan #migrants turned back at int'l bridge into El Paso last night, today. Small children too. I filmed and interviewed. This is against US & international law. pic.twitter.com/KBui4C3PT1

The blocking works this way: In the precise middle of the international bridges, CBP agents stand, sentry-like, near the imaginary line dividing the two countries — a line often marked with a ceremonial metal plaque. The agents peer at everyone crossing, looking for people they think might be candidates for asylum. If the people say anything suggesting they might be requesting asylum — if they’re not Mexicans, and especially if they’re from Central America — the agents block their way and say to come back another time.

Yet this has been happening, not just at El Paso but also at ports of entry all along the southern border. Immigration rights advocates first noticed that asylum-seekers were being turned away at some bridges shortly after the election of Donald Trump, and the practice continued into 2017. A Southern California immigrant advocacy group, Al Otro Lado, responded by suing U.S. Immigration and Customs Enforcement for violations of U.S. immigration law and the Constitution. The suit is ongoing.

Under the Immigration and Nationality Act, immigrants within the U.S. who tell immigration officials they’re afraid to return to their countries have the right to request asylum and to be immediately processed. They are not supposed to be turned back at bridges. They are not supposed to be banished to life on Mexican sidewalks, by public toilets, begging passersby for tacos to feed their children.

Based on that experience and on other information he has gathered, Garcia believes that the sudden day-in, day-out presence of CBP agents on the bridges, and their routine turn-backs of Central Americans and other migrants, is something new and disturbing.

In late May, Garcia and some volunteers at his shelters began visiting the bridges and taking statements from Central Americans who’d been denied entry.

Local people who frequently cross the border started noticing the agents in early May, but did not know why they were on the bridge. Some people started calling Ruben Garcia, director of Annunciation House, a migrant shelter which encompasses a network of satellite shelters. The shelters have for years maintained a close relationship with ICE. They regularly take in immigrants who’ve been picked up by the Border Patrol, processed, and released by ICE pending the results of their immigration cases. Garcia says he is very familiar with how many people the government picks up from week to week, and with how much of their own space CBP and ICE have to process people.

In El Paso, Garcia believes that the government’s claims of “no room” in 2016 and 2017 might have had some merit. “Back then, there really were a lot of Central Americans coming, and I know the government was overwhelmed in El Paso because we were overwhelmed at our shelters,” Garcia said. But now, he said, the situation has changed: “The numbers are down at our shelters. And if they’re down at our shelters, they’ve got to be down at the government’s facilities.” Garcia said those facilities include interview rooms at ports of entry. He can’t imagine they are overtaxed. Yet, he said, Central Americans stranded at the bridge constantly tell him that CBP agents say there’s “no room” to process the migrants.

Garcia said he asked a low-level CBP agent, who was working at an international bridge, why Central Americans were being blocked. “This is a borderwide policy,” Garcia said the agent answered. Garcia believes the policy is connected to Attorney General Jeff Sessions’s “zero tolerance” policy initiated in early May.

That is when the Trump administration began routinely splitting up immigrant adults and children who were caught crossing into the U.S. Most were families from Central America.

By blocking asylum-seekers from crossing legally, CBP is pressuring them to cross illegally. Garcia believes that this new practice gives the government an excuse to split up even more families.

“By putting officers on the bridge,” said a CBP spokesperson, the agency “is taking a proactive approach to ensure that arriving travelers have valid entry documents in order to expedite the processing of lawful travel.”

Depending upon port circumstances at the time of arrival, individuals presenting without documents may need to wait in Mexico as CBP officers work to process those already within our facilities. The number of inadmissible individuals we are able to process in a day varies based on the complexity of the cases, resources available, medical needs, translation requirements, holding/detention space, overall port volume and enforcement actions. As in the past when we’ve had to limit the number of people we can bring in for processing at a given time, we expect that this will be a temporary situation.

Amber Ramirez, a former immigration paralegal, came to the same conclusion earlier this month after she saw social media posts on Facebook about CBP agents blocking asylum-seekers on the international bridge.

Ramirez, 25, crosses frequently between El Paso and Juárez. On her way to El Paso one day after looking at Facebook, Ramirez saw a group of people who looked distressed. Speaking with them, she learned that all were from Guatemala: a 16-year-old girl and a woman with a frightened preschool-aged daughter. The teenager told Ramirez they had been prevented from crossing for days. They said they were considering coming into the U.S. by wading and walking under the bridge.

Ramirez knew that the wading and walking would result in the mother being criminally prosecuted and separated from her child, so she decided to act, even though she felt shaky. “My whole life, I’ve been scared and intimated” by border agents, she said. She gathered the teenager, the woman, and the child. She walked them to the top of the bridge.

Once there, she noticed that one CBP agent was standing north of the border, well within the United States. Ramirez then looked at the Central Americans and realized that they inadvertently had stepped forward. They were in the United States, too.

The agents tried to get Ramirez and the group to take a few steps backward, into Mexico. Instead, the group stayed politely but stubbornly in place. A quiet standoff ensued.

A supervisor arrived and seemed angry. Ramirez tried hard to remember the text of the Immigration and Nationality Act, the part about “aliens” in U.S. territory having the right to claim asylum. She wanted to quote it to the supervisor, but apparently he already knew the law. She remembers him scowling but waving the Central Americans past the blockade and toward the port of entry.

Two days later, on June 4, I saw the Guatemalan man with his 15-year-old son walking south on the bridge to Mexico. The man said they had just been prevented from crossing by CBP blockade for the sixth time in three days. I asked if he and his son would walk back again, with me behind them, filming. He agreed.

At the top, something similar to Ramirez’s experience occurred. When the agents saw us, they noticed that I was taking a video with my phone and seemed flustered. While telling the man and his son that there was “no room,” they stepped backward into the U.S. The Guatemalans stepped forward.

I noted to the agents that the Guatemalans were now in the U.S. and now had the legal right to request asylum. “It’s not that we’re not going to help them — it’s a capacity issue,” one agent said. The two shifted from foot to foot, and one called a supervisor. The Guatemalans stolidly held their ground in their first few inches of America.

The supervisor arrived, assessed the situation, and waved the father and son northward. I followed. The supervisor’s walkie-talkie squawked to officials farther down the line that asylum-seekers were coming to the port of entry along with a reporter.

Suddenly, another Guatemalan father-and-son pair came up behind us. I’d earlier met and filmed them, too. They said they had decided to follow me when they saw I was walking behind the others. This second family had also been denied entry many times. Now, they had also just been let through.

Inside the port, a gray-haired CBP agent peered at the four Guatemalans’ wrinkled identity papers, which the fathers had fished from old plastic bags. In a pleasant voice, the agent asked, “Are you afraid to return to your country?”

“Yes,” said the Guatemalans.

“Step this way.”

I said goodbye and good luck to the Guatemalans.

But without advocates or press at their sides, other immigrants are still not getting past the bridge blockade. On June 9, two journalists — Bob Moore, a freelancer, and Claudia Tristán, of El Paso’s KFOX-TV — stood on the southbound side of the bridge, where they were not immediately visible to the CBP officials. Each pointed their phones toward the northbound side and filmed a woman — whom they later determined was a Honduran asylum-seeker — and her small son walking several feet into the United States. Their videos show the two being turned back to Mexico.

Karolina Walters is a staff attorney at the Washington, D.C.-based American Immigration Council, one of three groups representing plaintiffs in the Al Otro Lado lawsuit. She says these turn-backs of people already on U.S. soil constitute civil rights violations and “get to the heart of the lawsuit.”

The day after the journalists made their turn-back videos, Garcia called a community meeting to recruit volunteers to go to the bridge in shifts. Almost 50 people came to the meeting — a very impressive number for El Paso, Garcia said. Similar gatherings have been underway during the past several days in other Texas border cities.

Garcia is training some of his recruits to go to the bridges in shifts and take notes when they see refugees being turned back from requesting asylum. He has another group that is learning to accompany the immigrants to the invisible line. He hopes those volunteers will be able to help asylum-seekers exercise their rights in the face of blockading border agents.