At least eight government soldiers have been arrested on suspicion of rape and looting in the Democratic Republic of Congo, says the UN mission there.
The men, including a senior officer, are accused of having raped at least 13 women in Fizi town in the east of the country earlier this month.
The army has been accused of rights abuses before, but arrests are rare.
UN troops came in for criticism last year for failing to stop mass rape by rebels in a town in a nearby region.
More than 300 women, men and children were raped by a coalition of rebel groups in Luvungi in North Kivu within miles of a UN base in August.
Eastern DR Congo is still plagued by army and militia violence despite the end of the country's five-year war in 2003 - and the conflict has become notorious for the sexual abuse of women and girls.
The rapes in Fizi, South Kivu province, are reported to have taken place on New Year's Day when soldiers attacked the town.
The medical charity Medecins Sans Frontieres said it had treated more than 30 raped women after the attack and provided them with drugs to reduce the risk of HIV-infection.
Some of the women were beaten with rifle butts, tied up with ropes or sexually assaulted in front of their children, the group said.
The soldiers are also suspected of having looted several houses and shops.
UN spokesman Martin Nesirky said its provisional report had found 13 women were raped and 19 others suffered various abuses, while the assailants also looted 14 shops, Reuters news agency reported.