* Death toll linked to Ebola outbreak has reached 70
* Virus reaching capital could increase population at risk
* Victims have also died in Sierra Leone and Liberia (Recasts; updates number of suspected cases in Conakry)
By Saliou Samb
CONAKRY, March 28 (Reuters) - Authorities in Guinea scrambled on Friday to halt the spread of Ebola in the capital as the Health Ministry identified ...