Secretary of State Hillary Clinton on Tuesday offered US help to punish perpetrators of soaring sexual violence in the Democratic Republic of Congo as she paid a lightning visit to its war-weary east.

Leaving aside her government jet for a small UN plane, Clinton became the highest ranking US official to tour the desolate lakeside town of Goma to highlight a rape epidemic afflicting tens of thousands of women.

Clinton offered personal comfort to two rape survivors, one of whom was violated when she was eight months pregnant with the fetus ripped out.

Speaking later to reporters as she flew on to Nigeria, Clinton said she felt "overwhelmed" by what she saw.

"It is almost impossible to describe the level of suffering and despair," Clinton said of the region torn by conflict with Hutu militants, some tied to the 1994 genocide in neighbouring Rwanda.

Clinton met with President Joseph Kabila in a tent outside the governor's mansion in Goma for what she described as "a very frank discussion" on sexual violence -- including calling on him to arrest key officers accused of rape.

"We believe there should be no impunity for the sexual and gender-based violence committed by so many, and that there must be arrests, prosecutions and punishments."

Clinton pledged 17 million dollars in new US funding for victims of sexual violence. She said the money would go to hire female police officers sensitive to victims' needs and to provide medical and psychological care for some 10,000 survivors.

"In the face of such evil, people of goodwill everywhere must respond," Clinton said in Goma. "This problem is too big for one country to solve alone."

Clinton also offered the help of the US military's Africa command to advise on how to stop sexual assaults, as well as US legal experts to draw up laws to prevent exploitation of minerals -- a key source of funding for the violence.

Congolese forces, backed by Rwanda, launched an offensive in January to flush out the Hutu militant Democratic Forces for the Liberation of Rwanda (FDLR).

Despite her concern about sexual violence, Clinton voiced support for the campaign and called for a regional solution to stabilise the former Zaire, where some 2.5 million people died between 1998 and 2001 in what has been called Africa's first continental war.

"We believe there can be more done to protect civilians while you are trying to kill and capture insurgents," she told reporters after meeting Kabila.

Her motorcade then whisked along one of the town's only paved roads as she headed to a camp for some of the nearly two million people displaced by more than a decade of conflict in the region.

Visiting the Mugunga camp, home to some 20,000 displaced people, the top US diplomat spoke with a 32-year-old mother of six, Chantal Mapemdo, who told her that she and other women were too scared of violence by men to return to lives in the fields.

Staying in the crammed camp with such poor hygiene that diarrhoea is a key threat, Mapemdo has begun an alternative livelihood for women weaving baskets, an initiative Clinton saluted.

Clinton looked at her firmly and said: "I just came back from meeting President Kabila and I told him we want to stop the violence so you can go home."

According to the United Nations, at least 200,000 women have been raped in eastern DR Congo since 1996.

The United Nations says that both militia fighters and troops are responsible for the sexual crimes.

Victoria Akyeampong, the acting representative of the UN High Commissioner for Refugees in DR Congo, said that many fighters operated with virtually no higher command to keep them in line.

"It is not an excuse, but there are unruly troops who have not been paid for months. They decide to pillage what they find and they pillage women and girls as well," Akyeampong said.

Clinton flew back to Kinshasa late Tuesday and later flew to Nigeria, where she will hold broad discussions on building a closer US relationship with the regional power.