The United Nations on Friday demanded an "independent" probe after dozens of people were killed in a crackdown on an anti-UN protest in eastern Democratic Republic of Congo (DRC).

UN rights office spokeswoman Ravina Shamdasani told reporters in Geneva that there was need for an investigation, stressing that the perpetrators need to be brought to justice.

Shamdasani noted that the UN is in touch with the DRC authorities to ensure that the probe the country opened was independent, effective, and that measures were put in place to ensure that future demonstrations are policed in line with international human rights standards.

According to an assessment by the rights office, at least 43 people were killed, including a policeman, and 56 got injured, when soldiers on Wednesday stopped a religious sect from holding a demonstration against UN peacekeepers in Goma.

The document also said soldiers arrested 168 people, including the leader of a Christian-animist group named the Natural Judaic and Messianic Faith Towards the Nations, as Shamdasanim revealed that at least 222 people were reportedly arrested, including women and children, warning that the risk of human rights violations in such charged context was high.

Eastern DRC has been ravaged by militia violence for three decades, a legacy of regional wars that flared in the 1990s and 2000s, as the UN peacekeeping mission in the country cost an annual budget of about $1 billion, according to the rights office.