LAGOS, Nigeria (AP) -- Nigeria's government has largely ignored years of "mass murder" in two central states, Human Rights Watch charged Thursday, failing to prosecute known perpetrators who have burned victims alive and hacked and shot to death others because of their tribe or religion.
The New York-based advocacy group presented a new report in Nigeria with details of "horrific sectarian violence" that has left more than 3,000 dead since 2010 in Plateau and Kaduna, states along Nigeria's 10th Parallel where Christianity and Islam meet and often clash.
In the absence of justice, people have taken to revenge killings, further fueling the cycle of violence, the organization said.
Nigeria's government did not immediately respond to requests for comment and routinely ignores such reports.
Human Rights Watch warned that Islamic militants waging an uprising in northeastern Nigeria have "invoked the lack of justice for attacks on Muslims" in these communities to justify killing Christians, including suicide bomb attacks on church services in Plateau and Kaduna states that killed dozens and sparked renewed sectarian clashes.
Violence in the area is rooted in religion, tribe, politics and a competition for land and water resources complicated by politicians who side with their religious or tribal group, leaving others feeling aggrieved.
It involves sedentary farmers who are mainly Christians and semi-nomadic Fulani cattle herders who are mainly Muslim. A farmer might steal or kill cattle that damage his crops. Then herders attack his village. Christians retaliate by raiding a Muslim neighborhood.
The Human Rights Watch report of more than 100 pages carries testimony from more than 180 witnesses and victims as well as police investigators, prosecutors, defense lawyers, judges, and community leaders, along with observations from the group's researchers.
They visited villages that have been "ethnically cleansed" of Fulani people in apparently orchestrated attacks by Christians in the past year.
In most cases, police round up hundreds at the scene of an attack, fail to take statements, hold them for a few days and then charges are quietly dropped, the report said.
Some people identified as killers never are arrested: Witnesses said they run into people they saw killing family members, going about their business freely, according to the report.
It gave the example of a 19-year-old student who watched her Christian history teacher stab her Muslim father to death, even as she pleaded with him that his victim was her dad. And a Christian man told researchers that he recognized Muslim neighbors among attackers who surrounded his village, killed two Christians and set their church ablaze.
"The witnesses knew the perpetrators of these crimes, but none of the perpetrators has been brought to justice," the report said.
Police fail to act because they are from the same group as the attackers, or demand bribes from people filing complaints who may have lost all their belongings, or take bribes to free arrested suspects, the report said.
The government has tried to deal with the conflict as a political, rather than criminal matter, setting up commissions of inquiry that have served to reinforce impunity, with their reports shelved, recommendations rarely implemented and perpetrators never brought to book.
"In the absence of effective remedies through the criminal justice system, similar violence continues to threaten these states, as aggrieved individuals seek retribution for the loss of their loved ones, homes, and livelihoods," it said.
Only 74 people have been convicted to date, Human Rights Watch said, 48 of them Christians including two pastors sentenced to five years' jail for burning Fulani homes. The longest jail terms, 15 years, were given to 15 Fulani men convicted on terrorism charges.
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