The Ebola outbreak raging in eastern Congo has claimed more than 1,000 lives — and violence in the region is impeding official efforts to combat the deadly disease.

Treatment centers in the towns of Butembo and Katwa have come under repeated attack from rebel groups. The conflict forced international aid groups to pull out of both areas, where 1,008 people have died of the gruesome disease, a government official said Friday.

A World Health Organization epidemiologist was killed last month during an assault on a hospital in Butembo.

The outbreak of the highly contagious virus — which causes uncontrollable bleeding and is fatal in 50% of cases — is the second-worst on record, after the 2014-16 outbreak in West Africa that killed more than 11,000 people.