Deadly election-related and communal violence in northern Nigeria following the April 2011 presidential voting left more than 800 people dead, Human Rights Watch said today. The victims were killed in three days of rioting in 12 northern states. Nigeria's state and federal authorities should promptly investigate and prosecute those who orchestrated and carried out these crimes and address the root causes of recurring inter-communal violence.

The violence began with widespread protests by supporters of the main opposition candidate, Muhammadu Buhari, a northern Muslim from the Congress for Progressive Change, following the re-election of incumbent Goodluck Jonathan, a Christian from the Niger Delta in the south, who was the candidate for the ruling People's Democratic Party. The protests degenerated into violent riots or sectarian killings in the northern states of Adamawa, Bauchi, Borno, Gombe, Jigawa, Kaduna, Kano, Katsina, Niger, Sokoto, Yobe, and Zamfara. Relief officials estimate that more than 65,000 people have been displaced.

"The April elections were heralded as among the fairest in Nigeria's history, but they also were among the bloodiest," said Corinne Dufka, senior West Africa researcher at Human Rights Watch. "The newly elected authorities should quickly build on the democratic gains from the elections by bringing to justice those who orchestrated these horrific crimes and addressing the root causes of the violence."

The presidential election divided the country along ethnic and religious lines. As election results trickled in on April 17, and it became clear that Buhari had lost, his supporters took to the streets of northern towns and cities to protest what they alleged to be the rigging of the results.

The protesters started burning tires, and the protests soon turned into riots. The rioting quickly degenerated into sectarian and ethnic bloodletting across the northern states. Muslim rioters targeted and killed Christians and members of ethnic groups from southern Nigeria, who were perceived to have supported the ruling party, burning their churches, shops, and homes. The rioters also attacked police stations and ruling party and electoral commission offices.