More than 100 people have been killed in clashes in the Jonglei state in southern Sudan, officials have said.
The clashes erupted after fighters from the Lou Nuer tribe raided a village belonging to a rival group on Sunday morning.
The extent of the carnage, however, emerged on Monday after officials reached the remote settlement.
A total of 51 villagers and 28 soldiers, national security and police officers guarding the settlement were killed, Kuol Diem Kuol, an army spokesman, said.
"From the attackers 23 bodies were found on the ground. These attackers were found in uniform with arms and organised in a military organisation in platoons with G3 rifles," he said.
"This is not a raid for cattle but a militia attack against security forces," he said.
Members of the Lou Nuer tribe earlier this month denied that their fighters had joined militias.