The World Health Organization is warning on Tuesday that the Ebola epidemic in West Africa may explode in the coming days as the disease spreads exponentially. In the three West African nations most stricken by the outbreak of the deadly hemorrhagic fever, the WHO warned that there could soon be as many as 5,000 to 10,000 new cases per week by December.

“The outbreak is still expanding geographically in Guinea, Sierra Leone and Liberia and accelerating in capital cities, Bruce Aylward, the WHO’s assistant director-general in charge of the Ebola response, said in a briefing with reporters in Geneva,” Bloomberg reported. “There have been about 1,000 new cases a week for the past three to four weeks, he said.”

Aylward added that there are presently around 1,000 new cases diagnosed per week, but warned that the infection rate is likely to expand dramatically. If the Ebola crisis is not resolved soon, “a lot more people will die,” he warned.

“As of Tuesday morning, 8,914 Ebola cases and 4,447 deaths had been reported to WHO,” USA Today reported. “Alyward stressed that the true number of deaths and infections is probably much higher.”

Some portions of the Ebola-affected areas of West Africa are, however, reporting fewer cases of the disease than in past weeks. Aylward cautioned that data collection in these regions may be difficult and warned against drawing any conclusions from the reduction in new cases.

“Is the epidemic slowing down, or are we not seeing the exponential growth?” Aylward told conference attendees. “Quite frankly, it’s too early to say.”

The WHO, which had previously estimated the mortality rate for the strain of Ebola spreading globally to be approximately 50 percent, increased that estimate on Tuesday to 70 percent. “The virus has killed more than 2,300 people this year in the country, including 95 health workers,” A Voice of America report revealed, after noting that another United Nations medical worker who contracted the virus while treating the infected in Africa passed away on Tuesday.