By Aaron Ross
MUKONDO, Democratic Republic of Congo (Reuters) - Nsange's troubles began with an affair. Pygmy residents of the village in southeastern Democratic Republic of Congo caught a Bantu man in bed with a married pygmy woman last year.
Retribution was swift: a group of pygmies beat the Bantu to death.
The killing sparked a vicious series of reprisals in this corner of mineral-rich Katanga province. Each side scrambled to form militias, armed with machetes and bows and arrows, that unleashed an orgy of execution, pillage and rape.
Hundreds of its pygmy residents fled. "I just followed the crowd," recalled Lubula Amunanzo, who walked 200 km (120 miles) northeast with her husband and five children to reach the village of Mukondo.
For two decades, high-profile rebel groups, often with foreign sponsors, have ravaged Congo's lawless east, where more than 5 million people have died since a 1998-2003 civil war.
But recently, a more local conflict has surfaced as one of the principal drivers of a humanitarian crisis in Katanga that the United Nations has labeled "catastrophic".
The conflict in Katanga, a vast province known for its rich deposits of copper and valuable metals, pits the Luba, a Bantu ethnic group, against the Twa, a pygmy people who inhabit the Great Lakes region of Central Africa.
The inter-ethnic fighting that broke out last spring has accounted for 77,000 displacements - the vast majority of them pygmies - in the Tanganyika district of Katanga's northeast, according to the United Nations.
The conflict between the Luba and the Twa has long roots. As in much of Central Africa, pygmies, traditionally a hunting and gathering people, have been denied access to land and basic social services.
Backed by civil society groups, Congo's Twa have escalated their calls for equal rights, rankling the Bantu.
"It's a problem of a part of a community that refuses the emancipation of another population," said Rogatien Kitenge, a spokesman for the Civil Society of Tanganyika.
Atrocities by the Bakata Katanga, a militia advocating the province's secession from Congo, poured fuel on the tensions.
In three years, the number of displaced in Katanga has leapt from 50,000 to over 582,000 as the militia has waged running battles with the army. With most of the violence far to the north of mining operations near the provincial capital Lubumbashi, output has not been affected.
The Mai Mai, dominated by Luba, accuse the Twa of collaborating with the army. In May 2013, militia members attacked the villages of Lwela and Nsange, where they burned 20 women and nine children alive, destroying some 200 houses.
More than 1,300 pygmies forced from their homes in Nsange and nearby villages have settled in Mukondo, where they live down the road from the Bantu inhabitants in thatched huts shielded from the rainy season downpours by white UNHCR tarpaulins.
"The Bantus here are different from the Bantus there," said Esau Sango Shabani, head of the pygmies' organizing committee.
The army and U.N. peacekeepers have deployed additional forces to the conflict zones and stepped up mediation.
Aid workers and officials credit intervention by authorities and U.N. agencies for tamping down the violence, which threatened to spiral out of control over the summer.
But some humanitarians say the local government has been slow to react to a politically sensitive issue. Congo's President Joseph Kabila is a Luba from northern Katanga.
District commissioner Jean Felix Ilunga Mpafu blamed a "poorly transmitted" call for integration directed at the pygmies by local activists: "The message was badly conveyed, going so far as to say (to pygmy women) that it was necessary to start sleeping with Bantu men."
Kitenge said that until gaping social inequities between Luba and Twa were addressed, conflict could resurface. "The water might be calm, but you can have crocodiles inside."
(Editing by Daniel Flynn and Tom Heneghan)