The UN's new pointman on Ebola was due to arrive in west Africa on Thursday for a visit aimed at shoring up health services in the region where at least 1,350 lives have been lost to the virus.
David Nabarro, a British physician appointed last week by UN Secretary Ban Ki-moon, said he would focus on "revitalising the health sectors" in Guinea, Liberia, Nigeria and Sierra Leone.
"One of the major issues is that health sectors and health services in countries affected by Ebola have really suffered," Nabarro told reporters in New York ahead of his trip.
Nabarro will travel to Monrovia, Freetown, Conakry and Abuja as part of his overall mission to coordinate the global response to the worst-ever outbreak of Ebola.
His visit comes at a time when some of the affected countries are struggling to contain the spread of the killer disease.
Violence erupted in an Ebola quarantine zone in Liberia's capital Wednesday when soldiers opened fire and used tear gas on protesting crowds as they evacuated a state official and her family.
Four residents were injured in the clashes that flared in Monrovia's West Point slum which has been sealed off as part of tough new security measures aimed at containing the deadly virus.
Liberian President Ellen Johnson Sirleaf has ordered a nightime curfew and the quarantine of West Point and Dolo Town, to the east of the capital.
Residents of West Point, where club-wielding youths stormed an Ebola medical facility on Saturday, reacted with fury to the crackdown, hurling stones and shouting at the security forces.
"It is inhumane," resident Patrick Wesseh told AFP. "They can't suddenly lock us up without any warning, how are our children going to eat?"
Liberia, with 576 deaths from 972 diagnosed cases, has seen the biggest toll among the four west African countries hit by Ebola.
Fighting the spread
Deaths from the epidemic that has swept through west Africa since March now stand at 1,350 after a surge of 106 victims in just two days, according to the World Health Organization (WHO).
Fears that the virus could spread to other continents have seen flights to the region cancelled, and authorities around the world have adopted measures to screen travellers arriving from affected nations.
Vietnam said Wednesday it had released two Nigerian air travellers from isolation after their fevers subsided. In Myanmar a local man is still undergoing tests after arriving from Guinea with a fever.
Countries throughout Africa and beyond remain on high alert, with the Equatorial Guinea airline, Ceiba Intercontinental, the latest to suspend flights to the whole region.
From its initial outbreak in Guinea -- where 396 people have died so far -- the virus spread to Liberia, Sierra Leone and Nigeria, overwhelming inadequate public health services already battling common deadly diseases such as malaria.
Straining the situation even further, several top officials leading the fight have lost their lives to the disease.
A doctor who treated Nigeria's first Ebola patient was named among the dead on Tuesday, taking the death toll in Africa's most populous country to five.
Efforts to contain the epidemic have also run up against local distrust of outside doctors, and stories of aid workers carrying the infection.
WHO spokeswoman Fadela Chaib noted "encouraging signs" in Nigeria and Guinea, where prevention measures and work to trace lines of infection were starting to take effect.
The Nigerian outbreak has been traced to a sole foreigner, a Liberian-American who died in late July in Lagos. All subsequent Nigerian victims had direct contact with him.
In Sierra Leone, where 374 people have died, the outbreak has also been traced back to one person: a herbalist in the remote eastern border village of Sokoma.
No cure or vaccine is currently available for Ebola, which is spread by close contact with body fluids, meaning patients must be isolated.
Given the extent of the crisis, the WHO has authorised largely untested treatments -- including ZMapp and the Canadian-made VSV-EBOV vaccine, whose possible side effects on humans are not known.
Three doctors in Liberia who had been given the experimental US-made ZMapp are reportedly responding to the treatment.
Researchers also said Wednesday an experimental drug treatment can help monkeys survive an otherwise deadly infection with a tropical virus called Marburg, which is similar to Ebola.