It is the first such expression of regret for Belgium's colonial past by a reigning monarch.
The countries along Congo's eastern border have long been conduits for gold worth billions of dollars mined using rudimentary means by so-called "artisanal" miners.
An epidemic of the virus on the other side of the country has killed more than 2,200 people since 2018.
MDA chief: 'We are happy to share knowledge... for the sake of saving human lives'
The prime minister spoke with President of the Democratic Republic of the Congo Félix Tshisekedi and Georgian Prime Minister Giorgi Gakharia.
The attackers fled after United Nations peacekeepers arrived at the village and they later fired on a nearby UN base, a UN source said.
On April 17, a 28-year-old motorbike taxi-driver who had tested positive for Ebola ran away from the centre where he was being treated in the town of Beni.
Ebola causes fever, bleeding, vomiting and diarrhea and spreads among humans through bodily fluids. The current outbreak has killed about two thirds of those it infected.
He told ministers the available evidence pointed to death by hanging, according to the minutes of the meeting.
Tshisekedi, who became president last year, credited his Christian faith and thanked American Evangelicals for their support for the Jewish state.