Three asylum seekers have tested positive for coronavirus in a sprawling encampment steps from the US border in Matamoros, Mexico, marking the first cases in a settlement that advocates have long viewed as vulnerable amid the pandemic, Reuters reported.

“For months, public health experts have sounded the alarm that people in these under-resourced migrant encampments and shelters... face disproportionate risks from COVID-19,” Michele Heisler, medical director at U.S.-based nonprofit Physicians for Human Rights, said in a statement.