Attackers have killed a Pakistani peacekeeper in an ambush in strife-torn eastern Democratic Republic of Congo, the United Nations announced.
UN leader Ban Ki-moon was "appalled" by the latest attack on UN peacekeepers on Tuesday and an investigation has been started, said spokesman Martin Nesirky.
The attack was staged in South Kivu province on a UN mission military convoy "by unidentified assailants," Nesirky said.
Various armed groups operate in South Kivu but it is not a stronghold of the M23 group, which launched an offensive against DR Congo government forces and UN peacekeepers in North Kivu province late last year.
Ban "condemns in the strongest terms the killing of a Pakistani peacekeeper in this attack. He recalls that the killing of peacekeepers is a war crime that falls under the jurisdiction of the International Criminal Court," said his spokesman.
The UN leader "offers his sincerest condolences and sympathy to the family of the victim, and to the government of Pakistan."
Ban called on the DR Congo government to "bring the perpetrators of this crime to justice," Nesirky added.
Pakistan is a key contributor to the UN force in DR Congo, officially known as MONUSCO, which is one of the biggest in the world with more than 17,750 troops and military observers and 1,400 police.
The UN Security Council voted in March to create an additional intervention brigade of more than 2,500 troops in eastern DR Congo to take on armed groups such as M23.
The special force, the first to be given an offensive mandate, is expected to start deploying in coming weeks and will be made up of troops from South Africa, Malawi and Tanzania.