An Ebola scare was reported in Calabar, southern Nigeria, a year after the country was declared free of the virus.
Ten people have been quarantined after coming into contact with a man showing Ebola-like symptoms, officials said.
The man reportedly died shortly after being admitted to hospital in Calabar.
On Wednesday, the three countries worst affected by Ebola – Guinea, Sierra Leone and Liberia, recorded their first week with no new cases since the outbreak began in March 2014.
More than 11,000 people died in the West African Ebola outbreak, the worst known occurrence of the disease in history.
New cases have fallen sharply in 2015, but the World Health Organization (WHO) has warned that the disease could break out again.
The latest scare happened when a patient arrived at the University of Calabar Teaching Hospital on Wednesday.
“We have sent blood samples for testing and quarantined identified contacts,” said Queeneth Kalu, the hospital’s chief medical director.
Those quarantined included nurses who had attended to the patient, he added.
Ebola arrived in Nigeria in July 2014 when a Liberian businessman collapsed at Lagos airport. In all, 19 people were infected of whom seven died.
WHO declared the country Ebola free in October last year.