(New York City)
The scale of the Ebola outbreak appears to be "vastly underestimated", the UN's health agency says, as the death toll from the disease reaches 1,069.
The World Health Organization said its staff had seen evidence that the numbers of reported cases and deaths do not reflect the scale of the crisis.
It said in a statement that "extraordinary measures" were needed.
The outbreak began in Guinea in February and has since spread to Liberia, Sierra Leone and Nigeria.
The Ebola outbreak began in February.