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 Rmy 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 neighbors, 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