The UN's rights chief has asked the Democratic Republic of Congo to investigate death threats against Nobel Peace laureate Denis Mukwege.

Dr Mukwege said that he received death threats after commenting about the killing of 18 people in South Kivu province last month.

Dr Mukwege is a gynaecologist and has a clinic in that area.

He shared the Nobel Peace Prize in 2018 for his work on sexual violence in war.

The UN rights chief Michelle Bachelet called for an impartial probe into the threats.

President Felix Tshisekedi pledged last week that the government would investigate the threats and ensure Dr Mukwege's security.