South Sudan's military spokesman says two clashes between soldiers and rebels resulted in the deaths of 33 people.

Col. Philip Aguer said Wednesday that South Sudan troops killed 28 fighters led by the rebel leader David Yau Yau in the restive state of Jonglei. Ten soldiers were wounded in the Monday fights.

Later Auger said the rebels ambushed the troops, killing five of them.

Pibor County Commissioner Joshua Konyi said there have been several government efforts to reach a peace agreement with Yau Yau but they have not succeeded. Konyi said it appears Yau Yau understands "the language of the gun" better than peace.

South Sudan broke away from Sudan in 2011 after decades of civil war. The country still has several internal regions where violence frequently flares.