KINSHASA, Congo — In the deadliest single attack on a United Nations peacekeeping mission in recent memory, rebels in eastern Congo killed at least 15 peacekeepers and wounded more than 50 others in an assault on their base that was launched at nightfall and went on for hours.
UN Secretary General Antonio Guterres expressed ‘‘outrage and utter heartbreak’’ and called the attack a war crime, urging Congolese authorities to swiftly investigate. The State Department’s Bureau of African Affairs said it was ‘‘horrified.’’
The peacekeepers killed were from Tanzania. At least five Congolese soldiers also were killed in the attack Thursday evening that has been blamed on one of the region’s rebel groups.