Thousands of desperate migrants are trapped in limbo and even at risk of death without food, water or shelter in scorching deserts and at sea, as governments close off borders and ports amid the coronavirus pandemic.

Migrants have been dropped by the truckload in the Sahara Desert or bused to Mexico’s desolate border with Guatemala and beyond. They are drifting in the Mediterranean Sea after European and Libyan authorities declared their ports unsafe. And about 100 Rohingya refugees from Myanmar are believed to have died in the Bay of Bengal, as country after country pushes them back out to sea.

Many governments have declared emergencies, saying a public health crisis like the coronavirus pandemic requires extraordinary measures. However, these measures are just the latest efforts by governments to clamp down on migrants, despite human rights laws.

“They just dumped us,” said Fanny Jacqueline Ortiz, a 37-year-old Honduran travelling with her two daughters, aged 3 and 12.

Ortiz reached the U.S., but American authorities expelled her to Mexico. The Mexican government in turn abandoned the family on March 26 at the lonely El Ceibo border crossing with Guatemala. Ortiz and other migrants on the two-bus convoy were told to avoid the Guatemalan soldiers guarding the border, which was closed due to the pandemic.

“They told us to go around through the mountains, and we slept in the woods,” she recalled.

Over the next few weeks, an activist helped Ortiz and others in her group of 20 find a ride to the next border, in Honduras.

Since the aftermath of World War II, international and some national laws have protected refugees and asylum-seekers. Even if states have the right to close themselves off for national security, they cannot forcibly return migrants to countries where they will face violence and other dangers, according to Dr. Violeta Moreno-Lax, professor of migration law at Queen Mary University of London.

Yet that is exactly what is happening.

“This is blatantly discriminatory and never justified,” said Moreno-Lax. “The pandemic provides the perfect excuse.”

The desert deportations have been happening for years in North Africa and beyond, and Europe has been deadlocked on how to handle migration on the Mediterranean since the 2015 migration crisis. In the United States, President Donald Trump made migration a central issue of his winning 2016 campaign and has unsuccessfully promised to put an end to border crossings from Mexico ever since taking office.

But this year, coronavirus has shifted the dynamic and allowed governments to crack down even harder, even as the desperation of those on the move remains unchanged.

In the United States, Trump is using a little-known 1944 public health law to set aside decades-old American immigration law. For the first time since the U.S. asylum system was created in 1980, Mexicans and Central Americans who cross the border illegally no longer even get the chance to apply for asylum. Instead, they are whisked to the nearest border crossing and returned to Mexico within hours; asylum-seekers at official crossings are also blocked.

Nearly 10,000 Mexicans and Central Americans were “expelled” to Mexico less than three weeks after the new rules took effect March 21, according to U.S. Customs and Border Protection. U.S. authorities say the decision was not about immigration but about public health.

Mexico then pushes the migrants further south. Mexico denies that it leaves migrants to fend for themselves, saying it coordinates with their home governments.

The very day Ortiz left El Ceibo, Mexico’s secretary for foreign affairs, Marcelo Ebrard, told The Associated Press: “No Central American is put anywhere in southern Mexico…. We are helping them return to their countries, when their countries and the migrant accept return.”

But the U.N. High Commissioner for Human Rights last week cited a cascade of borders from Mexico to Panama where thousands of migrants are caught out “in improvised camps, on the streets, or in shelters that have not always implemented health protocols to protect them.”

Migrants have also been left stranded in similarly makeshift conditions in the Sahara, after being expelled without warning from detention centers in Algeria and Libya. The expulsions aren’t new but have risen sharply as borders closed with the coronavirus.

Groups of dozens are walking 6 to 10 miles through the desert from a desolate no-man’s-land called Point Zero to the dusty frontier village of Assamaka in neighboring Niger. There, new arrivals must remain in makeshift quarantine for 14 days. After the quarantine, those from Niger can go home but foreigners are taken to U.N. transit centers in Niger, where they are stuck because air travel is suspended in and out of the country.

At the end of March, more than 800 people arrived in Niger in a single expulsion. Even after Algeria announced expulsions would be suspended because the border was closed, more people kept arriving every day under the punishing sun, including 100 earlier last week, according to the U.N.’s International Organization for Migration. More than 2,300 migrants are now stranded in Niger, unable to return home or anywhere else.

In Libya, the migrant detention center in Kufra expelled nearly 900 men and women from April 11 to 15, taking them by truck or bus across hundreds of miles of sand and leaving them either in a remote town in Chad or at a Sahara border post in Sudan, according to Lt. Mohamed Ali al-Fadil, the center’s director. Hundreds more came the following week.

Al-Fadil said the center is expediting operations, “deporting more people faster than ever before.” He said the expulsions are an attempt to shield migrants from the coronavirus, including those at the shelter. It’s not clear if there have been any virus outbreaks at the shelter. Libya, which is embroiled in internal warfare, has limited testing capacity.

“We fear for the migrants inside these shelters,” he said. “We must protect them.”

Yet the large groups of migrants forced out are in danger not only of the coronavirus but of midday temperatures that can rise to 120 degrees Fahrenheit this time of year.

Al-Fadil said the center coordinates with authorities in Chad and Sudan so the migrants aren’t abandoned in the desert. But the IOM has said those in Chad lack enough food, water and shelter and must quarantine in an open lot in Ounianga Kébir, a town in northern Chad hardly equipped for mass arrivals.

Tayeb Saleh, a 26-year-old migrant, was expelled from the Kufra detention center in Libya back home to Sudan. He said he and hundreds of other African migrants had languished for weeks at Kufra without clean water or food, awaiting deportation in the desert.

“The situation was unbearable,” he said. “I kept thinking if one of us had coronavirus, we would all die.”

Saleh was forced in late March into the back of a crowded truck, which then got stuck in the soft sand that swallowed its axle. After three to four days, he arrived in Sudan’s capital, Khartoum, where he recently emerged from quarantine in a jam-packed camp. He said he saw a dozen people left in the empty desert zone in Sudan.

Even for migrants who agree to go home and can reach their own borders, there’s no guarantee their home countries will accept them. Dozens of Egyptians deported from Libya were abandoned in the desolate border zone because they lacked identity papers, according to Ibrahim Larbid, the director of the Department for Combating Irregular Migration in the eastern Libyan city of Tobruk.

“The Egyptians won’t take them back in,” he said. “They must be left in neutral territory until they can retrieve their papers.” As far as he knows, they’re still there, awaiting paperwork that may not come for weeks, if ever.

Tunisia also blocked its own citizens from coming back from coastal Libya, leaving around 900 stranded and sleeping outside near an arid frontier post for weeks until they finally stormed the gates. Red Crescent officials said they expect the issue to flare again as more Tunisians try to return home for the Muslim holiday of Ramadan.

Hundreds of migrants are stuck not only in the desert but also at sea in the Mediterranean and the Bay of Bengal.

As of last week, the Mediterranean is going unpatrolled by rescue boats operated by aid groups. The last two such vessels are lashed together off the coast of Italy along with a ferry holding 180 migrants rescued in April, all of them in a 14-day waterborne quarantine within sight of the Italian town of Palermo.

The boats will ultimately dock. But no country has agreed to take in the migrants, who will stay on the ferry until their fate is decided.

“We’ve never seen states committing crimes of non-assistance in such a blatant light,” said Lorenzo Pezzani, a researcher for Forensic Oceanography, which investigates abuses in migrant rescues. “They’ve done it before but in a more covert way. But now there’s a total disrespect of any kind of humanitarian or legal framework. … It’s really worrying and troubling.”

The Libyan coast guard and the Maltese navy both suspended rescues in their own maritime zones, and Italy and Libya this month declared their own ports unsafe — meaning any commercial ship that picks up migrants at sea has few places to take them. The best hope for thousands of migrants trying to leave Libya’s squalid detention centers or cramped smuggler’s warehouses for Europe now lies with commercial vessels that are likely to be reluctant to risk their profits during a global economic crisis.

“Libya is a slow death,” said Mohamed Abdullah, a 16-year-old from the war-ravaged Sudanese province of Darfur who lives in a one-room apartment in Tripoli after three years in detention centers. “It’s a gradual death of waiting. Yes, there are dangers at sea and then the virus in Europe….but at least death by sea is quick.”

That calculation may be wrong for migrants trapped in the Mediterranean with no shelter or hope of rescue, said Marco Martinez, captain of the quarantined Aita Mari rescue ship.

“In winter, in 48 hours you are dead,” he said. Now, with gentle winds and warmer weather, “you can make it 4 or 5 days, and you will not have water, no food.”

Half a world away, hundreds of Rohingya refugees are also stuck at sea in the Bay of Bengal. Weeks ago, they boarded at least two fishing trawlers, and are now stranded off the coast of Bangladesh.

Fishermen spotted the boats on April 20, and the United Nations refugee agency, UNHCR, said they may have been at sea for weeks without enough food and water. But the Bangladeshi government said it cannot sustain more refugees and still keep a handle on the coronavirus crisis.

Bangladesh’s foreign minister, A.K. Abdul Momen, said Bangladesh has already taken in 1.2 million Rohingya and won’t take any more.

“The countries whose coasts touch the sea where these boats are have equal responsibility to take care of them, since this is a humanitarian disaster,” he said last week. “They only ask Bangladesh, not anyone else, to take the responsibility.”

Malaysia has also denied entry to several other boats, each with dozens on board. Survivors of another drifting boat that ultimately made it to shore told the aid group Médecins Sans Frontières that around 100 people died waiting.

In her tiny bamboo home in the giant Rohingya refugee camp at Cox’s Bazar in Bangladesh, Rahima Khatun has been sleepless since her daughter left with her grandchildren on an arduous boat journey more than 50 days ago to join her son-in-law in Malaysia. The 60-year-old has not had any contact with her daughter, Nur Begum, since.

“I don’t even know whether they’re dead or alive,” said Khatun, who fled violence in Myanmar.

Though Khatun is not sure which boat her daughter and grandchildren are on, she has heard about the stranded trawlers who were turned back by Malaysia and are being refused entry into Bangladesh.

“If I had wings I would fly and go see where they are,” Khatun said, weeping on the phone. “They are not being allowed to enter either Bangladesh or Malaysia – just floating in the middle with no one to help them out.”

Hinnant reported from Paris; Debre reported from Los Angeles. Maria Verza contributed from Mexico City; Elliot Spagat in San Diego; and Shafiqur Rahman from Cox’s Bazar, Bangladesh.