GOMA, Congo — The British charity Oxfam says hundreds of people are being killed and raped and homes are being torched in eastern Congo as militias take advantage of a security vacuum while the army fights a new rebellion.

Country director Elodie Martel calls it a humanitarian catastrophe. He says, "We have reached a new depth of misery in Congo's conflict when massacres go virtually unnoticed."

Some quarter million people have fled their homes.

Mutinying soldiers launched the M23 rebellion in April and now control huge swathes of mineral-rich east Congo. As Congo's army redeployed, new militias have sprung up and old ones are reasserting themselves in battles often aimed at gaining control of mines.