The World Health Organization said Wednesday that the risk of Ebola spreading is high at national and regional levels in Congo and Uganda, but remains low globally.

The risk assessment came as the leader of the WHO team in Congo said the outbreak, which has led to over 130 suspected deaths, could last at least another two months as aid efforts intensified to stem the spread.

WHO has declared the Ebola outbreak a public health emergency of international concern, requiring a coordinated response. On Tuesday, it expressed concern over the "scale and speed" of the outbreak.

Worried residents in eastern Congo have reported rising prices for face masks and disinfectants following the outbreak of the rare type of Ebola, known as the Bundibugyo virus.

It spread undetected for weeks following the first known death, while authorities tested for another, more common Ebola virus, which came up negative, health experts and aid workers said. There are no approved medicines or vaccines for the Bundibugyo virus.