Photo: Contributed

Nigerian newspapers report the death of Liberian Patrick Sawyer in Lagos from ebola last week. Photograph: Sunday Alamba/AP

Liberia's president has closed all but three land border crossings, restricted public gatherings and quarantined communities heavily affected by the Ebola outbreak in the West African nation.

President Ellen Johnson Sirleaf described the measures late Sunday after the first meeting of a new taskforce she created and is chairing to contain the disease, which has killed 129 people in the country and more than 670 across the region.

A top Liberian doctor working at Liberia's largest hospital died on Saturday, and two American aid workers have fallen ill, underscoring the dangers facing those charged with bringing the outbreak under control.

Last week a Liberian official flew to Nigeria via Lome, Togo and died of the disease at a Lagos hospital. The fact that the official, Patrick Sawyer, was able to board an international flight despite being ill raised fears that the disease could spread beyond the three countries already affected — Liberia, Guinea and Sierra Leone.

There is no known cure for Ebola, which begins with symptoms including fever and sore throat and escalates to vomiting, diarrhea and internal bleeding. The disease spreads through direct contact with blood and other bodily fluids as well as indirect contact with "environments contaminated with such fluids," according to the World Health Organization.

"No doubt, the Ebola virus is a national health problem," Sirleaf said. "And as we have also begun to see, it attack our way of life, with serious economic and social consequences."

Sirleaf said all borders would be closed except for three — one of which crosses into Sierra Leone, one that cross into Guinea and another that crosses into both. Experts believe the outbreak originated in southeast Guinea as far back as January, though the first cases weren't confirmed until March. That country has recorded the most deaths, with 319. Sierra Leone has recorded more of the recent cases, however, and has seen 224 deaths in total.

Liberia will keep open Roberts International Airport outside Monrovia and James Spriggs Payne Airport, which is in the city.

Sirleaf said "preventive and testing centres will be established" at the airports and open border crossings, and that "stringent preventive measures to be announced will be scrupulously adhered to."

Other measures include restricting demonstrations and marches and requiring restaurants and other public venues to screen a five-minute film on Ebola.

Sirleaf also empowered the security forces to commandeer vehicles to aide in the public health response and ordered them to enforce the new regulations.

Ebola in the country has also claimed the life of a doctor.