GENEVA (Reuters) - A surge in Ebola deaths reported by the World Health Organization at the weekend arose from about 1,000 Liberian deaths wrongly ascribed to the disease, the WHO said, and were removed from an updated data set released on Monday.

The revised data from the World Health Organization shows the three worst hit countries have suffered 5,987 deaths, nearly 1,000 fewer than previously reported.

"Liberia's figures came in but they've since said these were actually non-Ebola deaths that were reported as part of our Ebola deaths and we will be taking them off. So the whole world went up and the whole world will come down again," WHO assistant director general Bruce Aylward told reporters.

Data published at the weekend put Liberia's death toll at 4,181, up from 3,016 two days earlier. The WHO's new set of figures published on Monday showed Liberia with a death toll of 3,145 out of 7,635 cases as at Nov. 28.

Sierra Leone had almost as many cases, with a cumulative 7,109 Ebola patients over the course of the epidemic, with 1,530 deaths. Sierra Leone has had 5,831 laboratory-confirmed Ebola cases, more than twice the number in Liberia, where the majority of Ebola patients are "suspected" or "probable" cases.

The third worst-hit country, Guinea, has had 1,312 deaths out of 2,155 cases, the WHO data showed. The number of deaths in Mali was shown as six, one less than in the previous data release on Friday, out of eight cases.

There was no accompanying text to explain the figures.

(Reporting by Tom Miles; Editing by Mark Heinrich)