Dozens of health workers fighting an Ebola outbreak in the Democratic Republic of the Congo (DR Congo) abandoned several medical facilities on Thursday to protest months of unpaid wages.

The Central African country has struggled to contain the Bundibugyo strain, which has infected around 4,000 people and killed more than 1,800 since the outbreak was declared in May. The World Health Organization (WHO) has described it as the fastest-growing Ebola outbreak on record.

The workers rallied outside the governor’s office in Bunia, the capital of eastern Ituri province, news agencies reported. Ituri accounts for nearly 90% of confirmed cases, according to the WHO and the Africa Centres for Disease Control and Prevention (Africa CDC).

The protesters, including nurses treating Ebola patients, said they had not received wages or bonuses since mid-May. AP reported that they left several health facilities to join Thursday’s demonstration, further disrupting the response.

“With this way of managing things, Ebola will not end in this province,” protester Edouige Makosi told the news agency, urging the authorities to resolve the dispute quickly.

The action followed earlier protests in July, when Ebola response workers demonstrated outside three treatment centers in Bunia and accused the authorities of failing to pay them fully.

The authorities have reportedly blamed logistical difficulties for the delays. However, Africa CDC Director-General Jean Kaseya said on Thursday that the Congolese government had assured him it had the money to settle the workers’ salaries.

“We will not hear again about strike of health workers. Salaries will be paid, and the government... told me that they have money to pay health workers,” he said.

Kaseya said funding released for the Ebola response had exceeded $700 million following an additional $242 million pledge from the US.

“Money is not an issue today,” he said, arguing that the challenge was ensuring resources reached communities and frontline operations.

Africa CDC and WHO have called for health workers to be protected, equipped and paid on time. The continent’s health watchdog also announced plans to scale up the response and go “door to door” looking for patients amid serious gaps in contact tracing.

The outbreak has spread beyond Ituri to four other eastern provinces. No vaccine or specific treatment has been approved for the Bundibugyo strain, although clinical trials are underway.

Also on Thursday, the authorities quarantined nearly 200 passengers from a riverboat near Kinshasa after a traveler who had disembarked in Mongala province nearly three weeks earlier died with Ebola-like symptoms. All passengers were tested, although no cases have been confirmed in the capital.