The number of deaths attributed to an epidemic of Ebola virus in Guinea, Liberia and Sierra Leone stood at 467 by Monday, out of 759 known cases in total, the World Health Organisation (WHO) says.
The outbreak of the deadly disease is already the largest and deadliest ever, according to the WHO, which previously put the death toll at 399 as of June 23, out of 635 cases.
The 17 per cent rise in deaths and 20 per cent jump in cases in the space of a week will add urgency to an emergency meeting of 11 West African health ministers in Accra, Ghana on Wednesday and Thursday, which aims to co-ordinate a regional response.
In response to the outbreak, Liberian authorities have on Tuesday warned that anyone caught hiding suspected Ebola patients will be prosecuted. Some families, faith healers and traditional doctors were reported to be removing patients from hospital for special prayers and traditional medicine.
Liberian President Ellen Johnson Sirleaf said in a statement that the crisis has become a national public health emergency, urging people to heed health guidelines.
"It is illegal under our public health law to expose the people to health hazard such as Ebola," Sirleaf said in a statement seen by Reuters on Tuesday.
"Let this warning go out, anyone found or reported to be holding suspected Ebola cases in homes or prayer houses will be prosecuted under the laws of Liberia," she said.
The outbreak in West Africa has left some of the world's poorest states, with porous borders and weak health systems undermined by war and misrule, grappling with one of the most lethal and contagious diseases on the planet.
The WHO said three key factors were contributing to the spread of the disease. One was the burial of victims in accordance with cultural practices and traditional beliefs in rural communities. Another was the dense population around the capital cities of Guinea and Liberia. The third was commercial and social activity along the borders of the three countries.
"Containment of this outbreak requires a strong response in the countries and especially along their shared border areas," the statement said.
The WHO figures include confirmed, probable and suspected cases.