At least three WHO health workers have been killed and several more injured after two Ebola response centres in eastern Congo came under attack on Thursday.
Local militia, known as Mai Mai, also simultaneously attacked Ebola centres in Mangina in North Kivu and Byakoto in Ituri.
"It is a blow to the Ebola response because we were eradicating the disease. These attacks are challenging the efforts to date," said Jean-Jacques Muyembe, head of the Ebola response for the Democratic Republic of Congo.
The Mai Mai claim Ebola does not exist, and believe the response is a plot to eliminate the local population.
The second Ebola epidemic has left 2,199 people dead since the outbreak was announced in August 2018.
UN 'deeply disturbed' by strike on Iran school that killed 160 children
Saudi confirms attempted attack on oil refinery, no damage
At least four killed in Israeli strike on building in Lebanon's Baalbek
Kuwait announces death of child from shrapnel wound
Philippine lawmakers advance impeachment of Vice President Duterte
