LAGOS, Nigeria -- The victims of Sunday's sectarian massacres in central Nigeria were buried in mass graves Monday, as survivors told horrific stories of Christian villagers being trapped in nets and hacked to death by Muslim herdsmen.

Reports on the death toll differed wildly, with some placing it at about 200 and others reporting 528 killed and thousands injured.

Casualty figures in the recurrent Muslim-Christian violence in Nigeria's volatile Plateau State are often difficult to ascertain, as each side inflates its losses.

But attacks in January and on Sunday have left at least 500 dead, making it the region's worst violence for some years. Hundreds of nomadic Fulani herdsmen launched coordinated attacks on three Christian villages of Dogo Nahawa, Ratsat and Zot, just south of Jos at about 3 a.m. Sunday.

The killers planted nets and animal traps outside huts of the villagers, mainly peasant farmers, then charged while firing weapons, according to human rights lawyer Shehu Sani, of the non-government Civil Rights Congress, who visited the villages and interviewed dozens of survivors.

"People came out of their houses and started falling into the animal traps and mosquito nets, and then they were hacked down," he said. "They were the kind of traps used for wild animals."

Plateau State, which lies on the divide between the mainly Muslim north and largely Christian south, has seen thousands killed in the last decade. Fulani herdsmen have accused a group of indigenous Christians -- the Berom -- of attacking their camp last month, killing four people and stealing 200 cattle.

Violence in the region, which appears unrelated to ongoing national sectarian political tensions, has ethnic as well as religious overtones. Many clashes have involved rampaging mobs of the indigenous Christians and of Muslim settlers -- the Hausa, who started moving into the area early last century. The Muslim Fulani herdsmen, who move through the area with their cattle, are less often involved.

But this year's attacks have involved a more sinister pattern: carefully planned and brutal, with hundreds of villagers killed, including babies, the elderly and anyone else unable to flee.

"Even the kind of violence is unusual, because it was not physical confrontations between Muslims and Christians. It was an ambush. The attackers killed whoever they caught. It was mostly women, who stayed behind to defend their children, that became most of the victims," said Mr. Sani, the rights lawyer.

One survivor, Sylvanis Mathias, said the attack was well planned.

"They fired in the air, scared people out of their houses and then attacked them with machetes as they tried to escape and then burned their bodies. They set the houses ablaze. More than half of the houses have been burned."

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