The death toll in Angola from an outbreak of the rare Marburg virus has risen sharply to 146 people, the country's health ministry has said.
An Italian woman doctor working in Uige is among the dead
Twenty of the deaths have been reported since Thursday.
The outbreak, which began last October in Uige province, is the most serious ever recorded of the virus, a fast-spreading haemorrhagic fever.
Correspondents say there is a palpable fear in the capital Luanda that the Ebola-type disease could spread there.
The World Health Organization has sent 20 medical experts to Angola and is deploying field teams in the area of the outbreak.
Almost all the deaths took place in Uige, a northern province which borders the Democratic Republic of Congo.
About 75% of the cases involve children under the age of five. The victims include an Italian doctor who was treating people with the virus.
The Marburg virus has a high fatality rate and there is no known cure.
'Close to improving'
There are fears it could spread to Luanda, 300km to the south-west, where several of the victims died after arriving from Uige.
Reports say shops in the city are running out of household bleach, and parents are keeping their children out of school.
"Everybody is afraid of this virus. We don't know what it will do to us," a garage worker named as Antonio told AFP news agency.
But WHO Angola representative Fatoumata Diallo told AFP patients in Uige were now being isolated and treated.
"The situation is close to improving," he said.
The toll now exceeds the previous worst outbreak recorded in Angola's neighbour, DR Congo, in 1998, when 123 people died.
Several countries have taken measures to try to halt the spread of the virus.
Early symptoms of Marburg are diarrhoea, stomach pains, nausea and vomiting, which give way to bleeding.
But experts say the symptoms are similar to those of malaria, amoebic dysentery or tuberculosis, making it difficult to identify.
Most of the Angolan deaths occurred between three and seven days after the onset of symptoms, the WHO said.
Marburg, a severe form of haemorrhagic fever, has no known vaccine or medical treatment.
The infection was first identified in 1967 among laboratory workers in Europe who had been working with monkeys.