Monrovia, Liberia — Three new Ebola cases have been confirmed in Liberia, a health official said Friday, more than two months after the West African nation was declared Ebola-free for a second time.

It is a setback for Liberia, one of the three countries hit hardest by the worst Ebola outbreak in history. The country has recorded more than 10,600 cases and more than 4,800 deaths, according to the World Health Organization. More than 11,300 deaths have been recorded for the entire outbreak, which was concentrated in Liberia, Sierra Leone and Guinea, according to WHO.

Liberia was first declared Ebola-free on May 9, but new cases emerged in June resulting in two deaths. WHO declared the country Ebola-free again on Sept. 3.

The first of the latest cases, reported Friday morning, is a 10-year-old boy who lives in the eastern Paynesville district of Monrovia, said Dr. Francis Kateh, chief medical officer and acting head of Liberia's Ebola Case Management System. On Friday evening, Kateh said the boy's father and brother had also tested positive for the disease.

The three patients have been taken to an Ebola treatment center outside Monrovia along with three other people who were possibly exposed to the disease, said Sorbor George, the health ministry's communications director.

Officials were not sure how the new patients might have contracted Ebola, Kateh said.

The new cases in Liberia were announced just days after Guinea, the country where the epidemic started, said it had no more Ebola patients and was beginning a 42-day countdown toward being declared free of Ebola transmission. Guinea had been the last country with any cases, as Sierra Leone was declared Ebola-free on Nov. 7.