A Liberian doctor who was one of three Africans to be treated with an experimental Ebola drug has died.
Liberian officials on Monday confirmed the death of Dr. Abraham Borbor, who was deputy chief medical doctor at the country's largest hospital.
Borbor was one of three Liberia-based doctors to receive the drug ZMapp, which has yet to undergo clinical trials. There was no update on the other two doctors.
Two U.S. aid workers treated with the drug have survived, while a Spanish priest who received it died.
The drug's U.S. manufacturer, MappBiopharmaceutical, has said its supply of the drug is exhausted and producing more will take time.
In another development, the United Nations says airlines that have stopped flights to countries with the Ebola outbreak are hampering the response to the epidemic.
U.N. spokesman Stephane Dujarric said the action, although understandable, is not warranted. He said the flight boycotts are not an effective way to stop the virus, and are hampering the movement of international experts who are needed to control the outbreak.
The U.S. Agency for International Development has airlifted more than 16 tons of medical supplies and emergency equipment to Liberia to combat the regional Ebola outbreak.
The agency says the shipment includes two large water tanks, two water treatment systems, plastic sheeting for use in construction of Ebola treatment centers, and 10,000 sets of personal protective equipment.
Liberia has seen the greatest number of cases and deaths from Ebola, which has killed more than 1,400 people in West Africa this year.
Officials in the Democratic Republic of Congo, meantime, say two Ebola deaths have been confirmed in that country.
They say there is no known connection between the DRC cases and those in West Africa. Congo has seen numerous Ebola outbreaks since the virus was first discovered in 1976.
Ebola is transmitted through direct contact with blood or bodily fluids of an infected person. It can also be transmitted through consumption of bush meat such as bats.
The disease causes fever, vomiting, diarrhea and uncontrollable bleeding through bodily openings, including the eyes, ears and nose. Previous outbreaks have had a death rate of up to 90 percent, but the death rate in the current epidemic is closer to 50 percent.