The African nation of Sierra Leone has ordered a nationwide lockdown in an effort to combat the spread of ebola, a move most experts say they expect to be unsuccessful.

In fact, the lockdown could spread the disease further by concealing cases, medical charity Doctors Without Borders is warning.

The Sierra Leone government says it will order citizens to stay in the vicinity of their homes for a period of 3 days beginning Sept. 19, a move intended to stop an outbreak of new infections and allow health workers to locate people who have contracted the disease, the country's information ministry has announced.

Doctors Without Borders says past efforts at such lockdowns have proved ineffective.

"It has been our experience that lockdowns and quarantines do not help control Ebola as they end up driving people underground and jeopardizing the trust between people and health providers," the group, also known as Medecins Sans Frontieres, said.

"This leads to the concealment of potential cases and ends up spreading the disease further," said the group, which has been working to halt the spread of Ebola in West Africa during the world's worst outbreak of the viral illness.

First detected in March in Guinea, it has spread to much of Sierra Leone and Liberia, with cases also found in Senegal and Nigeria.

The World Health Organization has put the number of fatalities from the outbreak at more than 2,100.

Theo Nichol, Sierra Leone information minister, said the 3-day lockdown would give medical workers a better chance of tracking down suspected cases of Ebola.

However, Doctors Without Borders said such house-to-house tracking attempts would need a certain level of medical expertise, but even if cases are tracked down, there are insufficient numbers of treatment facilities to care for patients who might be identified.

The group has renewed its requests for developed nations possessing biological-disaster response know-how, either civilian or military, to deploy personnel and equipment to West Africa.

"This remains our best hope of bringing this deadly outbreak under control as quickly as possible," the group said.

The World Health Organization has expressed the belief it will require months to bring the Ebola outbreak under control, and expects there could be as many as 20,000 cases before that happens.

Ebola, also known as hemorrhagic fever, is cause by a virus. Symptoms begin with fever, muscle pain, sore throat and headaches, which can progress to vomiting, diarrhea, and failure of the kidneys and liver.

There is presently no known cure for the disease.