FILE PHOTO: A health worker wearing Ebola protection gear, prepares to  enter the Biosecure Emergency Care Unit at the Alliance for International Medical Action ebola treatment center in Beni, DRC, March 30, 2019.
FILE - A health worker wearing Ebola protection gear prepares to enter the Biosecure Emergency Care Unit at an Ebola treatment center in Beni, Democratic Republic of Congo, March 30, 2019.

A doctor fighting an Ebola outbreak in the Democratic Republic of Congo was killed in an attack on an eastern hospital, according to the World Health Organization.

Several gunmen from a local militia attacked the hospital in the city of Butembo, one of the epicenters of the Ebola outbreak, killing Richard Mouzoko, an epidemiologist from Cameroon.

WHO director-general Tedros Adhanom Ghebreyesus wrote on Twitter, "We are outraged by the attack. Health workers are #NotATarget."

A Congolese health ministry staffer and a driver were injured in the attack, according to a separate statement by the U.N. secretary-general's special representative in Congo.

Butembo's deputy mayor, Patrick Kambale Tsiko, said the attackers were targeting foreigners because they incorrectly believed the foreigners had brought the Ebola virus to Congo. He said police were searching for the attackers.

The violence is the latest in a series of attacks on Ebola treatment centers by militiamen and those distrustful of the international response to the outbreak.

Dozens of rebel groups are active in eastern Congo.

Earlier this week, Congolese President Felix Tshisekedi pledged more military and police protection for health workers fighting Ebola and asked residents for their cooperation.

The Ebola outbreak in eastern Congo's North Kivu and Ituri provinces began in August. Congo's health ministry says the outbreak has killed 843 people and infected hundreds more.

The epidemic is the second deadliest on record, after the Ebola outbreak that struck West Africa in 2014-16, which killed more than 11,000 people.