CAIRO (Reuters) - Libyan authorities have reported an outbreak of bubonic plague in the Mediterranean coastal town of Tubruq, and the World Health Organization was sending a team to investigate, a WHO official said on Tuesday.

The cases -- approximately 16 to 18 have been reported -- would be the first in more than two decades in Libya of the disease known in medieval times as the Black Death, according to John Jabbour, a Cairo-based emerging diseases specialist at WHO.

“It is reported as bubonic plague,” Jabbour said, adding WHO still didn’t have “a full picture” of the situation.

“It is officially reported by Libya... Tomorrow, WHO is deploying a mission to Libya to investigate the whole situation, to see how many of the cases are confirmed, or not confirmed.”

He said preliminary information from Libyan authorities showed 16 to 18 reported cases including one death, and that Tripoli had asked for assistance from the global health body.

Bubonic plague, noticeable by black bumps that sometimes develop on victims’ bodies, causes severe vomiting and fever and still kills around 100 to 200 people annually worldwide. It can kill within days if not treated with antibiotics.

A plague epidemic of 1347 to 1351 was one of the deadliest recorded in human history, killing about 75 million people, according to some estimates, including more than a third of Europe’s population.

That pandemic was thought to have begun in Asia, then spread into the Middle East, Africa and Europe.

Tubruq, where the new cases were reported, is approximately 125 km from the Egyptian border and was the scene of previous plague cases decades ago, Jabbour said. Egypt, already fighting to contain an outbreak of the H1N1 flu virus, said it had no reported cases of plague.

Rodents carry plague, which is virtually impossible to wipe out and moves through the animal world as a constant threat to humans.

Globally the World Health Organization reports about 1,000 to 3,000 plague cases each year, with most in the last five years occurring in Madagascar, Tanzania, Mozambique, Malawi, Uganda and the Democratic Republic of Congo. The United States sees about 10 to 20 cases each year.