London: Fears that the west African Ebola outbreak could spread to other continents is growing, with European and Asian countries on alert and a leading medical charity warning the epidemic is out of control.

The US Peace Corps said it was pulling all 340 volunteers from Liberia, Sierra Leone and Guinea because of the spreading virus, while Liberia said it would close schools and consider quarantining some communities, the toughest measures yet imposed by a west African government to halt the worst Ebola outbreak on record.

Medecins Sans Frontieres said the crisis would only get worse and warned there was no overarching strategy to handle the outbreak.