GENEVA, August 15. /ITAR-TASS/. The number of reported Ebola virus cases and deaths "vastly underestimate the magnitude of the outbreak", the World Health Organization (WHO) said on Friday, citing evidence by medical staff battling the epidemic in Africa.

Officials warned the outbreak might rage for several more months. Latest reports put the death toll at 1,069 and the number of infected cases at 1,975, mostly in Guinea, Liberia, Sierra Leone and Nigeria. The UN agency has urged donors to allocate $100 million to combat the outbreak.

"WHO is co-ordinating a massive scaling up of the international response, marshalling support from individual countries, disease control agencies, agencies within the United Nations system and others," the organization said.

The UN World Food Programme is delivering food for one million people in the quarantined areas between Guinea, Liberia and Sierra Leone.

"WHO is mapping the outbreak in great detail to pinpoint areas of ongoing transmission and locate treatment facilities and supplies," the statement said, adding that computers and software had been supplied to affected countries to facilitate analysis and track the dynamics of Ebola's spread.

WHO pronounced Ebola an emergency of international significance a week ago. Guinea accounted for 377 Ebola-related deaths, the highest toll, followed by Liberia (335 deaths) and Sierra Leone (334).

In Nigeria, the most densely populated country on the African continent, three people have died from the virus.