Jan 7 Armed Nuer tribesmen killed at least 139 members of a rival tribe in an attack in a remote area of southern Sudan, an official said on Thursday.
A surge of ethnic violence has resulted in the deaths of more than 2,500 people and forced 350,000 to flee their homes in 2009, according to a report issued by ten aid groups.
The violence has raised fears for the stability of the oil-producing territory, which secured a referendum and a semi-autonomous government in a 2005 peace deal that ended more than two decades of civil war with the north. The conflict, which also set southern tribe against southern tribe, left lingering resentments in a region already riven by traditional disputes over territory and cattle. Here are details of some of the worst fighting:
MARCH 5-13, 2009 - At least 453 people, mainly women and children, are killed in attacks by the Lou Nuer tribe on at least 17 villages of the rival Murle ethnic group in Jonglei. The Lou Nuer say the incidents were retaliation for large-scale cattle raiding and attacks on Lou Nuer villages in January.
APRIL 18-19 - At least 177 people are killed in attacks on 16 villages of the Lou Nuer tribe by Murle fighters. Women and children are targeted in what are widely seen as revenge attacks for the March violence.
JUNE 12 - Jikany Nuer, like the Lou a sub-group of the large Nuer tribe, attack barges carrying U.N. food aid on the Sobat River to Lou Nuer areas in Jonglei. At least 40 southern soldiers and boat crew are killed.
AUG. 2 - Murle attack a Lou Nuer fishing settlement near Akobo town in Jonglei State, killing 185 people. Southern soldiers guarding the camp are also killed.
AUG. 28 - Around 800 Lou Nuer attack Wernyol, a Dinka Bor village in Jonglei State, killing 38 and wounding 76. The south's army said this was the work of a Lou Nuer militia, adding that a Murle militia also exists.
SEPT. 20 - A large group of fighters from the Lou Nuer ethnic group attack Duk Padiet village, inhabited by the Dinka Hol tribe, in Jonglei. More than 100 people are killed.
OCT. 3-5 - At least 23 people are killed and 21 injured in tit-for-tat cattle raids between the Mundari and Dinka Bor tribes, the deputy governor of Jonglei state says.
NOV. 15-16 - A vehicle carrying South Sudan's Agriculture Minister Samson Kwaje is ambushed killing five and injuring the minister, the south's Internal Affairs Minister said.
-- At least seven people are killed during an attack by fighters from the Mundari tribe on the rival Dinka Aliap group in Awerial county in Lakes state.
DEC. 31 - Seventeen people are killed when armed civilians ambushed south Sudanese soldiers trying to disarm tribes following heavy fighting.
JAN. 2, 2010 - Nuer tribesmen attack Dinka cattle herders in Tonj East, a remote part of oil-producing south Sudan, and seize about 5,000 animals. At least 139 people are killed 54 wounded, a local official says.