Officials in South Sudan say at least 100 people have been killed and hundreds more wounded in renewed tribal hostilities.

The governor of Jonglei state, Kuol Manyang, outlined the casualty totals in a Monday news conference:

“The recent incident of death… committed by Murle youth in Akobo County in which a big number of people died, lost their lives, 200 others wounded and over 10,000 families displaced and thousands of cattle looted, and more details are coming in a daily basis.”

Akobo County commissioner Pal Mai said heavy fighting began Saturday and lasted the whole day.

The Murle and Lou Nuer tribes have traded increasingly heavy and deadly cattle raids in recent years.

The latest attack occurred on the eve of a disarmament program meant to ease tension in Jonglei state.

The fighting has undermined efforts to bring security and stability to South Sudan, the world's newest nation.