A measles outbreak has infected nearly 500 people in a native Brazilian tribe putting them at a high risk of death.
The indigenous Yanomami tribe live in a remote area near the Venezuelan border and are not protected from the disease, the Guardian reports.
Survival communications director Jonathan Mazower told the paper, "This disease is a potentially devastating one.
"It is extremely likely that people will die unless medical care is provided urgently and it is very likely that people in the forest have already died."
The Americas were declared measles free by the World Health Organisation in 2016, but outbreaks can still occur.
The Brazilian government says 200 cases have been confirmed at the border state of Roraima, where the Yanomami people live. Another 177 are being investigated.
More than 260 cases have been confirmed by the neighbouring state of Amazonas and 1368 are being investigated.
Newshub.
