BAMAKO (Reuters) - Around 20 United Nations peacekeepers placed under quarantine in Mali after they were potentially exposed to Ebola more than three weeks ago have been released, the country's U.N. mission said on Saturday. The soldiers were being treated at a clinic in the capital Bamako for injuries sustained while serving the mission, known as MINUSMA, in the north of the country when a nurse working at the facility died of Ebola. "Having all been placed under observation, the MINUSMA solders under quarantine have not presented symptoms of illness. They've therefore left the establishment," the mission said in a statement. While the mission has not released the nationality of the soldiers, U.N. sources have said they are from Chad. Mali registered eight cases of Ebola - seven of them confirmed and one probable - after the virus spread from neighboring Guinea, according to the World Health Organization (WHO). President Ibrahim Boubacar Keita said last week that the West African nation no longer had any confirmed cases of the disease after the last patient known to be suffering from the virus was cured. The worst Ebola epidemic on record has killed nearly 6,200 people, mainly in Liberia, Sierra Leone and Guinea, since it was confirmed in the region earlier this year, according to the latest WHO data.