The humanitarian agency said it was stepping up its operations, mainly to protect women and girls from sexual abuse in the vast eastern region where more than 100 rape victims seek help at its health centres each month.

Dominik Stillhart, deputy director of ICRC operations, also warned the crisis sparked by fighting between dissident groups and the army could still spill over into neighbouring countries.

"The armed violence observed against the civilian population has reached a scale and intensity that has not been seen since the height of the war in the year 2000," Stillhart told a news briefing upon his return from Congo, Rwanda and Burundi.

In a statement, the ICRC said it had "recorded an alarming number of violations of international humanitarian law, including rape, forced recruitment of minors, arbitrary executions and many cases of pillage."

All armed groups were committing crimes, a spokeswoman said.

More than 370,000 people have fled their homes this year, including 145,000 since fighting resumed between insurgents of Laurent Nkunda and the army three months ago, the ICRC said. The army has battled the renegade Tutsi general since he abandoned a peace deal in August.

Sexual violence by various armed groups had "sharply increased again in the past few months," according to Stillhart.

"What really shocked me personally most is the systematic violence, especially against women and girls, which is producing immense suffering in Kivu," he said.

A Congolese Red Cross worker who helps rape victims told him about a pregnant woman who fled her village when it came under attack by an armed group.

"She was hiding in the field when she was discovered by two fighters in uniform. They both raped the pregnant woman and when she tried to resist, one of the fighters shot her in the foot and they both left her in the field," he said.

"Later when her husband found her, the contractions had already started and he brought her to the health centre, where both the woman and the baby died during the delivery," he said.

The ICRC will further boost its activities in Congo, already its second largest operation in Africa after Sudan.

Its top priority will be protecting civilians and preventing sexual violence in Kivu, where it will double the number of expatriate staff it deploys to 20 from the current 10.

Medical facilities treating "war-wounded" -- Goma hospital, a health centre in Mushaki and a hospital in Nkunda-held Kitchanga -- will be expanded, according to Stillhart.

"There is always a risk for this conflict again to spread over the borders, although for the time being this risk has been contained," he added.