The tally of deadly Ebola cases in the Democratic Republic of the Congo ticked above 1,000 this weekend as health responders continue to struggle to thwart the disease amid violent conflict.

The outbreak has been raging since August in the country’s North Kivu and Ituri provinces, which sit on the eastern side of the country, bordering South Sudan, Uganda, and Rwanda. The World Health Organization reported 1,009 cases (944 confirmed, 65 probable), including 629 deaths (564 confirmed, 65 probable) on Saturday, March 23.

The outbreak is the second largest of all time, surpassed only by the 2014 West African outbreak, which involved more than 28,000 cases and 11,000 deaths.

Violent attacks and lingering distrust have hampered medical responses throughout the outbreak. Earlier this month, militants attacked a treatment center in the city of Butembo in North Kivu, killing a police officer and injuring health workers. Last month, Doctors Without Borders/Médecins Sans Frontières (MSF) suspended medical responses after two other attacks on treatment centers. In both attacks, unidentified assailants partially burnt down facilities.

“Although the reasons behind the attack are unclear and such violence is unacceptable, what we know is that the actors of the Ebola response—MSF included—have failed to gain the trust of a significant part of the population,” Meinie Nicolai, MSF’s general director currently in North Kivu, said in a statement after one of the attacks.

Officials at the World Health Organization called for renewed efforts to control the outbreak. “Despite the increased frequency of attacks by armed groups, WHO will stay the course and will work with communities to end this outbreak together with the Ministry of Health and partners,” Dr. Tedros Adhanom Ghebreyesus, WHO director-general, said in a statement Saturday. “We need redoubled support from the international community and a commitment to push together to bring this outbreak to an end.”

Tedros added that community fears of violence and the deadly virus run deep. “Community engagement takes time. There are no quick fixes,” he said.

Still, Dr. Matshidiso Moeti, WHO regional director for Africa, was pleased that the efforts so far have led to 96,000 people being vaccinated against Ebola. “We are working in exceptionally challenging circumstances, but thanks to support from donors and the efforts of the Ministry of Health, WHO, and partners, we have saved thousands of lives,” he said.