Sierra Leone officials have confirmed a death from Ebola, hours after the World Health Organization declared the latest West Africa outbreak over.
The country was declared free of the virus on November 7, and the region as a whole was cleared when Liberia was pronounced Ebola-free on Thursday.
Tests on a person who died in northern Sierra Leone proved positive, an Ebola test centre spokesman told the BBC.
The WHO has warned, however, that more flare-ups are expected.
The Sierra Leone death occurred earlier this week.
Ebola test centre spokesman, Sidi Yahya Tunis, told the BBC that the patient had died in the Tonkolili district. He had travelled there from Kambia, close to the border with Guinea.
The tests were conducted by British health experts.
The BBC reports that health officials were now urgently seeking those who had come into contact with the victim.
Close to 4,000 people have died of Ebola in Sierra Leone and 11,000 people across the region, since December 2013.