Fourteen UN peacekeepers have been killed and 53 wounded in a “huge” attack in the Democratic Republic of Congo.
UN peacekeeping chief Jean-Pierre Lacroix said he was “outraged” by the attack on a base in North Kivu province, thought to have been carried out by rebels from the anti-government Allied Democratic Forces (ADF) group.
In a statement, the UN Stabilisation Mission in Congo (MONUSCO) said the attack resulted in “protracted fighting” between suspected rebels and the Congolese army.
At least five Congolese soldiers were killed in the gunfight and UN spokesman Farhan Haq said the dead peacekeepers were mainly from Tanzania.
He added: “It’s a very huge attack, certainly the worst in recent memory.”
The peacekeeping base, located around 27 miles from the town of Beni, has been repeatedly targeted by ADF rebels.
It is home to MONUSCO’s rapid intervention force, which is tasked to “neutralise and disarm” groups considered a security threat.
UN secretary general Antonio Guterres expressed his “heartbreak” over the attack, which he called a war crime.
He said: “I call on the DRC authorities to investigate this incident and swiftly bring the perpetrators to justice. There must be no impunity for such assaults, here or anywhere else.
“Military reinforcements have arrived on the scene. The Force Commander is there as well, coordinating the mission’s response. The medical evacuation of casualties is ongoing.”
Mr Guterres added: “The situation in the DRC is one of the emergencies we are highlighting in today’s appeal for the Central Emergency Response Fund.
“This latest attack highlights the urgency of helping people in need and addressing the volatile situation.”
The rebel ADF movement has been active since the 1990s but has intensified attacks in Congo in recent years.
Human rights groups say its members have killed at least 1,000 people in the last three years.