A Tanzanian peacekeeper who served in the UN force deployed to troubled eastern Democratic Republic of Congo has died from injuries he sustained fighting rebels in August, the United Nations said Wednesday.

Lieutenant-Colonel Proper Basse, a spokesman for the UN force in the country, said Hugo Munga died on September 18 in a South African hospital.

Munga was hurt in clashes with rebels from the country's M23 movement in the Goma region, and is the second UN soldier and second Tanzanian killed since late August.

The UN Security Council approved the first-ever "offensive" peacekeeping brigade with orders to "neutralise" and "disarm" rebel groups operating in DR Congo's east in March.

The 3,000-strong contingent is staffed by South African, Tanzanian and Malawian soldiers.

The UN and various rights groups have accused the M23 of atrocities including rape and murder in a conflict that has caused tens of thousands to flee.

The M23 was founded by former rebels who were incorporated into the Congolese army under a 2009 peace deal.

Complaining the deal was never fully implemented, they mutinied in April 2012, turning their guns on their former comrades and launching the latest rebellion to ravage DR Congo's mineral-rich east.