South Sudan's army massacred civilians, burned children alive and gang-raped women after a supposed cease-fire with rebels in December, according to reports by monitors appointed by the country's East African neighbors over a five-year civil war.

South Sudan, which won independence from Sudan in 2011, has denied targeting civilians and called the reports, compiled in the last three months by the Juba-based CTSAMM monitoring group, exaggerated.

The 14 CTSAMM reports also accuse rebels led by former deputy president Riek Machar of using child soldiers, something a Machar spokesman denied.