Following earlier denials, Liberia has admitted that 17 suspected Ebola patients are “missing” after a health centre in the capital was looted.
The government had sought to reassure people, saying all the patients had been moved to another health facility.
But Information Minister Lewis Brown told the BBC that 17 inmates had gone “back into their communities”.
The World Health Organization (WHO) has called for exit screenings on all travellers from affected countries.
It wants checks at airports, sea ports and major land crossings.
More than 400 people are known to have died from the virus in Liberia, out of a total of 1,145 deaths recorded in West Africa by the World Health Organization this year.
Assistant Health Minister Tolbert Nyenswah said protesters in the West Point district had been unhappy that patients were being taken there from other parts of the capital, Monrovia.
Other reports suggested the protesters had believed Ebola was a hoax and wanted to force the quarantine centre to close.
The Ebola epidemic began in Guinea in February and has since spread to Liberia, Sierra Leone and Nigeria.
One Nigerian doctor has survived the disease and was sent home on Saturday night, said Health Minister Onyebuchi Chukwu in a statement.
Mr Chukwu said five other people infected with Ebola had almost fully recovered.
On Friday, the death toll rose to 1,145 after the WHO said 76 new deaths had been reported in the two days to 13 August. There have been 2,127 cases reported in total.
Ebola Virus Disease (EVD)
- Symptoms include high fever, bleeding and central nervous system damage
- Fatality rate can reach 90% – but current outbreak has about 55%
- Incubation period is two to 21 days
- There is no vaccine or cure
- Supportive care such as rehydrating patients who have diarrhoea and vomiting can help recovery
- Fruit bats, a delicacy for some West Africans, are considered to be virus’ natural host