WHO assistant director general Bruce Aylward said the number of burials and new admissions had fallen and laboratory-confirmed cases had hit a plateau, though he said there was no need to draw overly optimistic conclusions from the development, the online edition of Irish Independent reported
"All the data point in the same direction," he told a news conference. "Do we feel confident that the response is now getting an upper hand on the virus? Yes, we are seeing slowing rate of new cases, very definitely."
"We're seeing a reversal of that rapid rate of increase to the point that there seems to be a decline right now," he said.
Jeremy Farrar, director of charitable foundation the Wellcome Trust, made similar comments urging caution, adding the next few weeks would be crucial to locking in potential gains made through increased international support.
He told Reuters that he thought the last week would be seen as the week the jigsaw puzzle that changes the epidemic was put in place
Meanwhile, AP reported that health authorities had called for renewed vigilance over the Ebola epidemic and urged caution over claims it was retreating as the World Bank announced a $100-million fund for more health workers.
Meanwhile, international aid agency Doctors Without Borders said the slowdown could be due to sick people not being picked up due to a lack of ambulances which meant they were excluded from the statistics.
According to the charity, "mandatory cremation of dead bodies and a poor ambulance and referral system could also be reasons for this decrease in admissions".
"It is too soon to draw conclusions on the reduction of Ebola cases in Monrovia," Fasil Tezera, MSF head of mission in Liberia, said in a statement.
Liberia's health minister Tolbert Nyensuah said Liberia would not be able to consider itself Ebola-free, even if it reported no new cases, until neighbours Guinea and Sierra Leone had eradicated the virus.
Almost 5,000 people had died in the outbreak according to the WHO, almost all in Liberia, Guinea and Sierra Leone - while the number of cases registered worldwide had shot to 13,703.
World Bank president Jim Yong Kim announcing the $100 million donation, said, "We have to end this epidemic, there's just no other way around it. We've got to get to zero," he said, admitting the world had reacted too slowly and describing the economies of the three worst-hit countries as "devastated".