Updated at 5:45 p.m. ETIn the past 14 months, Algeria has either expelled or turned away more than 13,000 migrants and forced them to walk into the Sahara, according to a new report by The Associated Press.The news service says an increasing number of men, women and children expelled by Algeria have been sent into the desert, sometimes at gunpoint. In the Sahara, they must walk for miles to the nearest tiny town with a water source or get picked up by U.N. rescuers as they wander dehydrated in the blistering heat. Untold numbers have died, disappearing into the desert.You can read the full report on the AP's website.Pascal Reyntjens, the chief of mission in Algeria for the International Organization for Migration, confirms to NPR that "an increasing number of migrants" are reporting being dropped in the desert by Algerian authorities, which Algeria denies. Camille Le Coz, a policy analyst at the Migration Policy Institute who spoke to the AP for its story, tells NPR that Algeria has been deporting immigrants, including dropping them off in the desert, for years."What is new is the scale — the number of these forced returns," she says. "It's been a concern for NGOs, for civil society, for a number of months."While it's clear that the number of deportations is rising, it's not at all clear why, Le Coz says. She warns that there's no reliable data about overall migration in the area to confirm or deny explanations for the rise in deportations."Algeria gives very little access to what is really going on in the country," she says.The rise in deportations might be linked to a rising number of migrant attempts to enter Algeria, as the European Union has worked in adjacent Libya to shut down migrant and trafficking routes. Le Coz also notes that there are long-standing patterns of informal migration between Algeria and neighboring countries — people looking for temporary jobs, not just seeking to migrate north to Europe.Reyntjens, too, emphasizes the key role of regional economic migration — and, he notes, some of the migrants released in the desert might be laborers who were just trying to return home. "The way back is as dangerous and unpredictable as the way up," he says. It's also not clear how many people have died during crossings of any sort in the Sahara."It's very similar to the question of how many people die at the border between Mexico and the U.S.," Le Coz says. "It's impossible to know.""The desert doesn't bring back the bodies," Reyntjens says. "You disappear in the desert, you might disappear forever." All told, the International Organization for Migration tells the AP that migrant deaths in the Sahara since 2014 may number in the tens of thousands.Most of their stories will never be known. But survivors who were expelled from Algeria have harrowing accounts.One woman told the AP she gave birth to a stillborn child in the middle of the desert, burying him in a shallow grave. A young man from Senegal said the Algerian authorities stole his money and cellphone before turning him out into the desert, where he and 1,000 other people wandered aimlessly for hours.The AP reports: "The migrants' accounts are confirmed by multiple videos collected by the AP over months, which show hundreds of people stumbling away from lines of trucks and buses, spreading wider and wider through the desert. Two migrants told the AP gendarmes fired on the groups to force them to walk, and multiple videos seen by the AP showed armed, uniformed men standing guard near the trucks. "Algerian authorities refused to comment on the allegations raised by the AP. Algeria has denied criticism from the IOM and other organizations that it is committing human rights abuses by abandoning migrants in the desert, calling the allegations a 'malicious campaign' intended to inflame neighboring countries."In addition to the migrants deported on foot into the desert, thousands of migrants from Niger — which has an agreement with Algeria governing such deportations — are sent home in trucks and buses, the AP writes. Those trips, too, can be deadly.A spokesman for the UNHCR, the U.N.'s refugee agency, tells NPR in a statement that the agency is "deeply concerned" by the reports of indiscriminate, unsafe deportations from Algeria "without any due process.""While UNHCR recognizes Algeria's sovereign right to adopt measures to address irregular migration, collective expulsions are prohibited under international law, as countries are required to examine each case of expulsion individually," the statement says. "We are calling on Algeria to establish, prior to deportation, whether a person could be exposed to serious human rights violations. If such a risk exists, Algeria is precluded from forcibly removing the person concerned and is required to provide access to fair and efficient refugee determination procedures."UNHCR is following the situation very closely on the ground and will continue to cooperate with the relevant authorities in Algeria to ensure that persons in need of international protection are not affected by these operations."Other countries in North Africa, particularly Libya, have been accused of human rights violations perpetrated against migrants, including those bound for Europe — and the EU has been accused of complicity for encouraging crackdowns on migration in the region.In Libya, migrants and human rights groups say that captured migrants have been sold as slaves.NPR's Ruth Sherlock and Lama al-Arian report: "Boubaker Nassou, a 30-year-old from Gambia, describes the detention center where he was held as a 'slave market.' ... [T]he smugglers' car that Nassou rode in was detained by a militia once he crossed into Libya. The migrants were bundled into another vehicle, and he says they were taken 'straight to the prison where they sell people.' "It was a large, dank room, crammed full of African men and women. Nassou says he barely had space to sit or lie on the concrete floor. It was hot and no one was allowed to shower; the air was putrid. "And all the while, Nassou says, Libyans would come to haggle with the guards. What they were haggling over was the price for prisoners. He says a 'business' has developed of buying migrants out of one detention center and selling them to another for profit. ... "Libyan law has few provisions for asylum-seekers or protections for victims of human trafficking. It criminalizes irregular entry and punishes undocumented immigrants with fines or jail while they wait to be deported."And the deadly risks of the Mediterranean crossing have been widely reported on over the past few years.Earlier this year, Sherlock spoke to a man in Tunisia who collects and buries the bodies of migrants who wash up on the shore after drowning in the Mediterranean."When I see these people washing up on the shore, I feel that life has rejected them. So why should we reject them?" Chamseddine Marzoug said. "Why should we reject giving our African brothers a proper burial?"Marzoug's own sons made the perilous journey to Europe without telling him. They survived. Copyright 2018 NPR. To see more, visit http://www.npr.org/.