Democratic Republic of Congo's M23 rebel chief Sultani Makenga was being held by Uganda's  military, a senior officer said Thursday, after his insurgents suffered a crushing defeat to UN-backed government forces. "He is with our forces, yes, Makenga has crossed into Uganda with some of his men, he is with us," a senior Ugandan military officer told AFP, but refused to clarify if he had formally surrendered or was under arrest. The officer said "several" M23 troops had accompanied him, but would not give an exact number.