Filed at 9:37 p.m. ET

UNITED NATIONS (AP) — Congolese government troops are raping, killing and looting civilians in the same area of eastern Congo where militias carried out mass rapes over two months ago, a top U.N. envoy said Thursday.

Margot Wallstrom, who is responsible for U.N. efforts to combat sexual violence in conflict, told the Security Council U.N. peacekeepers have received reports of rapes, killings and looting by government soldiers.

"The possibility that the same communities who were brutalized in July and August by FDLR and Mai Mai elements are now also suffering" at the hands of the army "is unimaginable and unacceptable," she said, referring to the Rwandan-led rebels from the Democratic Front for the Liberation of Rwanda by their French initials.

Following the mass rapes that ended in early August, Congo President Joseph Kabila ordered a moratorium on mining in the mineral-rich area and sent in thousands of army troops to reassert government control.

"I am gravely concerned about the ongoing military operations ... in the Walikale territory and the implications for the protection of civilians," Wallstrom said.

She urged the government to investigate the allegations and deploy national police to the area to protect civilians and investigators. She said she had also asked U.N. peacekeepers to monitor and report daily on rapes and other sexual violence.

Wallstrom also called for U.N. sanctions against a Rwandan Hutu rebel commander over the alleged mass rapes of more than 300 people in eastern Congo. Sanctions could include an asset freeze and travel ban.

She offered to provide evidence to the council committee dealing with sanctions against Congo from witnesses who allege that "Lt. Col." Serafim of the FDLR was one of the commanders of mass rapes in the mineral-rich Walikale area from July 30 to Aug. 2.

Wallstrom praised last week's arrest of "Lt. Col." Sadoke Kokunda Mayele, accused of leading some 200 fighters from the Mai-Mai militia in the mass rapes in Walikale. He was turned in by members of his own militia because his own leader's family members were among those assaulted.

"When commanders can no longer rest easy in the certainty of impunity; when it begins to cross their mind that they may be turned in by their own for commissioning or condoning rape; this is the moment when we open a new front in the battle to end impunity," she said.

While the Congolese government should be commended for some policies adopted to combat sexual violence, she said, "so far 'zero tolerance' has been underpinned largely by 'zero consequences' for such crimes."

The United Nations said 303 civilians — 235 women, 13 men, 52 girls and 3 boys — were raped in 13 villages in the Walikale area. Even in eastern Congo, where rape has become a daily hazard and some women have been sexually assaulted repeatedly over the years, such numbers are shocking.

Wallstrom also urged that perpetrators of rape and sexual violence be barred from any amnesty provisions, from any benefits of disarming and returning to civilian life, and from any role in politics or government.

She said the mass rapes in Walikale demonstrate the link between the illegal exploitation of natural resources by armed groups and sexual violence. Therefore, she said, these rapes should also be investigated "from the angle of the competition over mining interests as one of the root causes of conflict and sexual violence."

Wallstrom encouraged European countries and other nations to enact legislation requiring companies to disclose whether their products contain minerals from Congo.