The first teams should begin work on Thursday amid fears an epidemic is imminent in the troubled west African state, which is trying to rebuild after 14 years of almost continuous civil war.

Three people have died who were confirmed as having the viral disease and another 11 suspected cases are undergoing laboratory analysis in neighbouring Ivory Coast, the world body said.

"Conditions are ripe here for an epidemic," said Dr Luzitu Simao from the World Health Organisation (WHO).

"The last 14 years of civil war have literally destroyed Liberia's health infrastructure and yellow fever is an extremely deadly disease. Even among hospitalised patients, the mortality rate may reach up to 50 per cent."

The World Health Organisation and the UN Children's Fund (UNICEF) said that fewer than 80,000 doses of the vaccine are now available in the country, far less than the 722,000 they set as their target.

The disease is mostly transmitted by mosquito bites and Liberia lies close to the so-called yellow fever belt on the African continent. There were at least six yellow fever outbreaks in the country between 1995 and 2002.

An interim government has only been in place in Liberia for a few months since former president Charles Taylor fled to exile in August, and the nation remains in dire need of reconstruction.

An international donors conference at the United Nations earlier this month raised 520 million dollars to help rebuild the country, which was founded by freed US slaves in the 19th century.

TERRA.WIRE