Reuters reported that Sierra Leone had declared a state of emergency and sent out its armed forces to quarantine epicentres of Ebola. Sierra Leone follows Liberia in imposing tough controls to curb the worst ever outbreak of the deadly virus amid global fears it could spread beyond West Africa.

The World Health Organization (WHO) said on Thursday The death toll from an outbreak of Ebola in West Africa has risen to 729 from 672 a week ago, after more deaths were reported in Guinea, Liberia, Nigeria and Sierra Leone over the weekend.

The outbreak of the hemorrhagic fever, for which there is no known cure, began in the forests of remote eastern Guinea in February, but Sierra Leone now has the highest number of death and infection cases. Ebola kills up to 70 percent of its victims within days.