The Democratic Republic of Congo army on Sunday said it has launched a new offensive against rebel fighters who fled to the hills after being ousted from their last stronghold. "We are pounding Mbuzi," General Lucien Bahuma told AFP by telephone. "After the artillery we will send in the troops." Some 200 die-hard fighters of the M23 rebel group have been holed up in the mountains of eastern DR Congo since their base in the town of Bunagana was seized on Wednesday.