JOHANNESBURG (AP) — The World Health Organization says Ebola responders are on lockdown in the eastern Congo city of Beni after angry residents attacked a United Nations base to protest repeated rebel assaults.

WHO director-general Tedros Adhanom Ghebreyesus says every day that health workers don’t have full access to Ebola-affected areas is a “tragedy” that prolongs the outbreak.

Beni residents are outraged that rebels continue to carry out deadly attacks despite the presence of U.N. peacekeepers and Congolese forces. Some demand that the U.N. mission act or leave.

Congo’s president after an emergency meeting Monday decided to allow joint operations between Congolese and U.N. forces in Beni following the protests that also burned the town hall.

The unrest hurts crucial efforts to contain the second-worst Ebola outbreak in history. Cases have been dropping.