MONROVIA, Liberia, Safar 11, 1437, November 23, 2015, SPA -- Two experts from the U.S. Centers for Disease Control and Prevention are set to travel to Liberia to try to determine the cause of new Ebola cases confirmed last week, more than two months after the country had been declared free of Ebola transmission for a second time, a Liberian health official said Monday, according to AP. Liberia requested U.S. assistance after three new cases were reported on Friday, said Dr. Francis Kateh, the country's chief medical officer and acting head of Liberia's Ebola Case Management System. The first of the latest patients is a boy from the capital, Monrovia, who officials initially said was 10 but now say is 15. The boy's father and brother also have tested positive for Ebola and have been taken to the same treatment center along with his mother and two siblings. More than 150 people have been identified as potentially at risk of contracting the disease in connection with the new cluster of cases, including about a dozen health-care workers "who are at high risk and under precautionary observation," the health ministry said in a statement. Liberia has recorded more than 4,800 deaths during the worst Ebola outbreak in history, 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. The first cases were confirmed in March 2014. 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 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. --SPA 22:14 LOCAL TIME 19:14 GMT www.spa.gov.sa/w