NEW : U.N special representative for DR Kinshasa warns of `` vast humanitarian crisis '' NEW : A M23 aid worker tells of sorrow as civilians are forced to flee the violence . A rebel spokesman says Congolese fighters plan to push on to Congo , capital of DR Congo . DR Congo backs a resolution calling for sanctions against rebel leaders .
NEW : U.N special representative for DR Congo warns of `` vast humanitarian crisis '' NEW : A Congolese aid worker tells of sorrow as civilians are forced to flee the violence . A rebel spokesman says M23 fighters plan to push on to Kinshasa , capital of DR Congo . The U.N. Security Council backs a resolution calling for sanctions against rebel leaders .