CAIRO — Over the course of Yemen's civil war, African migrants determined to reach oil-rich Saudi Arabia have endured unspeakable cruelties - torture, rape, detention, extortion - often perilously close to front lines.

Now, the coronavirus pandemic has dealt yet another blow to vulnerable migrants caught in Yemen's war zone.

Stigmatized as carriers of COVID-19, over 14,500 migrants, mostly Ethiopian, have been relentlessly hounded, rounded up and sent packing to different provinces, the U.N. migration agency reported on Tuesday. They remain stranded without adequate food, water or shelter.

"For nearly six years, Yemen has been an extremely unsafe place to be a migrant," Paul Dillon, spokesman for the International Organization for Migration told reporters in Geneva. "COVID-19 has made this situation worse; migrants are scapegoated as carriers of the virus and as a result, suffer exclusion and violence."

Last year, over 138,000 migrants desperate to find jobs as housekeepers, servants and construction workers in Saudi Arabia embarked on the arduous journey from the Horn of Africa to Yemen, according to IOM. Ethiopians traverse hundreds of miles from their home villages through countries like Djibouti or Somalia, then across the sea and through war-torn Yemen. In many cases, migrants are at the mercy of smugglers who may imprison and torture them, leave them stranded on the route or sell them into virtual slave labor.

But this spring that traffic came to a grinding halt, as countries closed their borders to contain the virus' spread. Movement restrictions curbed migrant arrivals in Yemen by 90%, IOM reported, while leaving the tens of thousands of Ethiopians in the country trapped in limbo.

With transportation between provinces at a standstill, thousands of migrants, blamed for spreading the virus, have been bussed from their makeshift homes and dumped in different provinces. At least 4,000 are stranded in the southern government-held city of Aden and 7,000 in the rebel stronghold of Saada, among other places, the IOM said.

The agency did not specify which authorities, whether Iran-allied rebel Houthis that control much of the country's north or Saudi-backed government forces, were responsible for the forcible transfers.

Saudi Arabia, which has struggled to contain a major outbreak of COVID-19, has continued its long-standing practice of expelling migrants who manage to make it into the kingdom. As of mid-April, Saudi Arabia had deported nearly 2,900 Ethiopians due to the pandemic, IOM reported at the time, and another 250 deportations were planned each day over the weeks that followed.

In May, Houthi authorities accused Saudi Arabia of deporting 800 Somali migrants and dumping them at the desert border.

On top of being deported and transferred against their will, migrants have been verbally and physically harassed as a result of mounting virus fears in Yemen, the agency added.

Although government authorities have recorded no more than 1,516 infections and 429 deaths as of Tuesday, aid workers and doctors say the virus is surging across the country and overwhelming a health system already in shambles after five years of war between the Houthis and the Saudi-led coalition backing Yemen's government. Long before the pandemic, the U.N. labeled Yemen the world's worst humanitarian crisis.

Migrants, many who sleep outdoors, in abandoned buildings or in squalid detention centers without access to medical care, are particularly vulnerable to infection, Dillon warned.

"There's no access to some of the basics that one would need to address public health concerns such as COVID-19," he said.

The Houthis have suppressed all information about the outbreak and refused to make infection figures public since they reported just four cases in May.

––and an ominous portent of retaliation to come.