Border Patrol officers have raided a humanitarian aid camp set up to give shelter and water to migrants crossing the scorching Arizona desert, in an operation that activists said puts lives at risk.

Four migrants were arrested during Thursday’s raid on a medical aid station run by the No More Deaths group near the small settlement of Arivaca, about 15 miles from the border and 60 miles south of Tucson.



The operation came as weather in the region heats up even more than normal, with temperatures predicted to rise as high as 114F (46C) in the coming days.

No More Deaths blamed the hardline immigration stance adopted by the Trump administration for the raid, which it said broke a longstanding agreement that border agents would respect the camp as a medical facility under international Red Cross standards and not interfere with its work.

“People crossing the deadly and remote regions of the US-Mexico border often avoid seeking urgent medical care for fear of deportation and incarceration. For this reason, a humanitarian-focused aid station in the desert is an essential tool for preserving life. The targeting of this critical medical aid is a shameful reflection of the current administration’s disregard for the lives of migrants and refugees, making an already dangerous journey even more deadly,” the group said in a statement.

Around 30 agents in 15 vehicles and a helicopter participated in the raid, said Julia Milan, a volunteer with No More Deaths. “It turns a humanitarian aid station into a trap … Our camp is 100% compromised right now,” she said.

“While they were waiting for the warrant to be served they were surveilling camp 24 hours a day for 48 hours. Of course that’s going to impede anybody from seeking medical care at the camp, from coming in and out. Also they set up a mobile checkpoint at the gate of the camp asking people about their citizenship status,” she said.

Margo Cowan, a lawyer for No More Deaths, said the raid marked a clear change in policy. “This is a very troubling development. It is also just a very radical change in the way that we have related to each other for 14 years,” she said.

“We’ve had skirmishes over the years with the Border Patrol but generally we’ve developed a very good working relationship with them. In some ways we have a mutual concern about saving lives,” she said.

“Over the years we’ve seen it all. We saw a guy with a rattlesnake bite next to his heart; every broken bone you can imagine; heat exhaustion; hypothermia; diabetic shock; had a woman that was picked up with a punctured lung as a result of fighting off a sexual assault attack.”

Deaths among migrants who make unauthorised crossings from Mexico and trek through remote parts of the desert to avoid federal agents and interior checkpoints are far from uncommon.

Sixty-one deaths have been reported in the state so far this year, according to the Arizona OpenGIS Initiative for Deceased Migrants, which recorded 169 deaths in 2016, though some activists suspect the true number is far higher.

In a statement, the Border Patrol said that it had detected “four suspected illegal aliens wearing camouflage and walking north on a known smuggling route. Other agents then tracked the group to the No Mas Muertes Camp near Arivaca but did not find foot sign of the individuals leading the camp.”

Agents then unsuccessfully tried to “resolve the situation amicably” with camp representatives, the statement added, before acquiring a search warrant and arresting the migrants.

Border Patrol said that “a similar incident” a month earlier resulted in eight people surrendering and being arrested, two of whom “had prior significant criminal records in the United States” and two who were taken to hospital.

Cowan questioned why the four migrants were not intercepted before entering the camp, if they were first spotted closer to the border.

“In our view this was a setup,” she said, adding that she fears the camp will be rendered ineffective if word gets around that Border Patrol is targeting it. “People are certainly not going to come if they think they’re going to be detected,” she said. “Undoubtedly people will die as a result of this action.”

Customs and Border Protection, the agency that directs the Border Patrol, said on Thursday that it is reassigning resources with a view to carrying out more rescues. ”Although Tucson sector employs more than 200 emergency medical technicians and more than 25 paramedics, there’s no guarantee that someone stranded in a remote area, for whatever reason, will be found in time to prevent the loss of life,” it cautioned in a statement.

“As an additional deterrent, the Border Patrol advises that individuals arrested crossing the border illegally in this identified high-risk area, will be presented for prosecution. Arizona’s desert shows no mercy for those unprepared for its remote, harsh terrain and unpredictable weather.”

Joanna Williams of the Kino Border Initiative, a binational migrant assistance group on the Arizona-Mexico border, said that threats of arrest and prosecution are unlikely to stop the flow of desperate people making the journey because of extreme violence or poverty in Central America. Instead, she believes, it encourages them to traverse more remote terrain and not to ask for help when they get into trouble.

“What we find is that actually deters people from calling from assistance, from calling 911 and turning themselves in when they’re in a life or death situation,” she said.

“We’re in the middle of an extreme heatwave, up to 120F in some parts early next week, so the timing of it was very problematic in the sense of we should be dedicating our energy and resources so that people don’t die in the desert.”