More than 200 people have now died in the latest outbreak of Ebola in the Democratic Republic of Congo, according to health officials.
About half the victims were from Beni, a city of 800,000 in the North Kivu region, the national health authority said.
A vaccination programme has so far inoculated about 25,000 people.
However, health minister Oly Ilunga said armed rebels were continuing to harass medical teams.
Congo has suffered from years of civil war and political upheaval.
The current outbreak of Ebola, which began in July, is the 10th to hit the country since 1976. The virus is spread via small amounts of bodily fluid and infection often proves fatal.
In its latest update, the health ministry said 291 cases had been confirmed and 201 deaths had been recorded.
Mr Ilunga said, on Friday, that teams had faced “threats, physical assaults, repeated destruction of their equipment and kidnapping”.
“Two of our colleagues in the Rapid Response Medical Unit have even lost their lives in an attack,” he added.
Last week, the World Health Organization’s director general, Tedros Adhanom Ghebreyesus, said the lack of security was posing the greatest challenge in countering the current epidemic.