Zambia said it would restrict entry of travellers from countries affected by the Ebola virus and would ban Zambians from travelling to those countries, in one of the strictest moves yet by a southern African country against the deadly virus.

Guinea also announced the closure of its borders with Sierra Leone and Liberia in a bid to halt the spread of Ebola, a virus that has killed nearly 1,000 people in the three countries this year.

"All delegates from any of the countries affected by Ebola virus disease are restricted from entering Zambia until further notice," the Health Ministry said in a statement posted on its website on Saturday.

The statement, which was dated August 8, also said that any Zambians arriving from those countries would be "thoroughly screened and quarantined", adding that no further travel by Zambians to such countries would be allowed.

At least 367 people have died in Guinea of Ebola since March and 18 others are being treated in the country in isolation, but the decision was taken primarily to avoid infected people crossing into the West African state, authorities said.

"We have provisionally closed the frontier between Guinea and Sierra Leone because of all the news that we have received from there recently," Health Minister Rémy Lamah told a news conference, noting that Guinea had also closed its border with Liberia.

The measures had been taken in consultation with the two neighbours, Guinea's Minister for International Cooperation, Moustapha Koutoub Sano, told the news conference.

The UN World Health Organization said on Friday that Ebola represents an international health emergency and could continue spreading for months.

Nigeria became the third African nation, after Sierra Leone and Liberia, to declare a national emergency on Friday as the region's healthcare systems struggle to cope with the advance of one of the deadliest diseases known to man. - Reuters