A UN base has been petrol-bombed in Beni, east of the Democratic Republic of Congo, amid worsening protests against the UN.
At least two other peacekeeping bases were also targeted on Thursday.
Casualty figures were not immediately clear.
At least 19 people including three UN peacekeepers have died in the violent clashes following anti-UN protests that started on Monday.
Demonstrators have been accusing the UN of not protecting civilians against armed groups operating in the east.
A UN spokesman says the protesters have been joined by Mai Mai militia groups, formed ostensibly to protect villagers.
More than 100 different armed groups operate in the east, including the Allied Democratic Front that is affiliated to the Islamic State group.
A recent wave of attacks has killed hundreds and displaced tens of thousands.