The Ebola virus recently killed 84 people in just three days, bringing the global death toll to 1,229, the World Health Organization said this morning.

The death toll, which passed the 1,000-mark over a week ago, soared higher from last Thursday to Saturday.

The number of confirmed infections jumped by 113 over the three days, bringing the total number of cases to 2,240, the UN health agency said.

The epidemic, which has hit four west African nations since it broke out in Guinea at the start of the year, is by far the deadliest since Ebola was discovered four decades ago in what is now the Democratic Republic of Congo.

Liberia was the hardest-hit country in the latest figures, with 48 new cases and 53 deaths.

That lifted its total count of cases to 834, with 466 deaths.

The new WHO toll predates an attack overnight Saturday on a quarantine centre in the Liberian capital Monrovia that caused 17 Ebola patients to flee. 

Liberia's information minister said all 17 were later found and transferred to the JFK Ebola specialist treatment centre.

He also said three infected African doctors who had received the experimental Ebola drug Zmapp were showing "remarkable signs of improvement", quoting an assessment by the doctor overseeing their treatment.

Sierra Leone recorded 38 new infections and 17 fatalities, the new WHO data showed.

As a result, Sierra Leone's total case count increased to 848 and its death toll to 365.

Guinea counted 24 new cases and 14 new deaths. That lifted the total number of cases to 543, with 394 deaths.

Nigeria, meanwhile, recorded three new cases but no deaths.

All told, Nigeria has now seen 15 cases and four fatalities, the data shows.

German health authorities have quarantined a 30-year-old Nigerian woman who showed symptoms consistent with the Ebola virus.

Dozens of visitors and staff at a Berlin employment office building were stopped from leaving for several hours as emergency services sealed off part of the street.

A number of people who were with the woman inside the building in the north eastern district of Prenzlauer Berg were also taken to hospital for tests.

The Bild newspaper said the woman had fainted and later said she had recently been in contact with people infected with Ebola.