(MENAFN- AFP) Tests on the first Ebola case in Liberia after a three month span when the West African country was declared Ebola-free are genetically similar to a 2014 outbreak, the UN health agency said Friday.

The World Health Organization said this showed that the resurgence of the disease was not likely due to the virus entering Liberia from two other Ebola-ravaged neighbours; Sierra Leone and Guinea.

Liberia said on June 30 that a 17-year-old died after contracting Ebola and transmitting the virus to two other people in the coastal region of Margibi.

Since then, two more people from the same village have been detected with the virus, taking the total number of confirmed cases to five.

"Tests on these samples have shown that the virus is genetically similar to viruses that infected many people in Margibi County more than 6 months ago, in late 2014," the WHO said.

"Because the virus appears to be related to the one previously circulating in Liberia, it is unlikely that this recurrence has been caused by virus imported from infected areas of Guinea or Sierra Leone," it said.

The world's worst Ebola outbreak has killed more than 11,250 people in West Africa, brought fragile health care systems to their knees, rolled back economic gains and sent investors fleeing.

Liberia suffered a setback when the new cases were uncovered after the hardest-hit country had been declared Ebola-free.

New infections in Sierra Leone and Guinea have fallen dramatically amid indications that the epidemic is largely under control.