The World Health Organization (WHO) is sending an expert to Libya to look into a reported outbreak of bubonic plague not far from the Egyptian border.
Libyan officials say at least one person has died and several more have been infected in the town of Tubruq.
Cases of the disease, which was known as the Black Death in medieval Europe, are reported quite frequently in sub-Saharan Africa.
Bubonic plague can be treated with antibiotics if diagnosed early.
The WHO received a request from Libya to investigate the suspected cases in Tubruq on Tuesday, spokeswoman Aphaluck Bhatiasevi said.
An expert is on his way to Tubruq where he will help a government team study epidemiological data and check the reported cases.
If confirmed, it would be the first outbreak in that part of Libya for about 25 years, Ms Bhatiasevi said.
The Associated Press news agency quoted a Libyan official as saying that two people had been treated and sent home, and 10 others turned out not to have the disease.
Plague primarily affects wild rodents, and is spread between them by fleas.
Humans who contract the plague through flea bites normally develop a bubonic form - in other words, a form that enters via the skin.
Besides Africa, cases have also been reported in some Asian countries and in the US in recent years.