JUBA (Reuters) - A south Sudanese rebel leader was killed Saturday, the southern army and a separate rebel group said as Africa's newest nation is trying to quell violence threatening stability.
South Sudan seceded from the north on July 9 -- a separation won in a January referendum that was the climax of a 2005 peace deal which ended decades of civil war with Khartoum.
The new state is struggling with poverty, underdevelopment and instability threatening its east African neighbors.
At least seven rebel militia are fighting government forces in remote parts of the oil-producing country.
Gatluak Gai, one of several militia commanders in the south, was shot dead by his own group in Unity state after having earlier agreed on a ceasefire with the government, said Philip Aguer, spokesman for the southern army known as SPLA.
"Gatluak Gai was killed by his deputy. It was an internal division. He (had) signed a peace (deal) with the SPLA," he said.
Aguer said Gai changed his mind about being integrated into the SPLA after agreeing to it earlier this week. The shooting started after an argument with his officers, he said.
"Gatluak Gai and three others were killed in the shooting," Aguer said.
But a separate rebel group headed by former southern army officer Peter Gadet said the SPLA had killed Gai. "Gatluak Gai has been killed by the SPLA. They shot him," spokesman Gatkuoth Kol said.
South Sudan's President Salva Kiir has renewed an offer of amnesty to armed groups fighting his government but previous pardons have had little success.
Many rebels say they are fighting against what they see as corruption and ethnic discrimination in the south's government, charges denied by the state.
More than 2,300 people have been killed in rebel and tribal violence in the south in 2011, according to the United Nations.
(Reporting by Jeremy Clarke. Writing by Ulf Laessing)