JOS, Nigeria (AP) -- The U.S. government and human rights activists called Tuesday for Nigeria to investigate and prosecute those responsible for the deaths of more than 200 unarmed people in renewed violence between Christians and Muslims.
Acting President Goodluck Jonathan had promised that the fighting would stop after more than 300 people were slain in January. Jonathan fired his national security adviser late Monday night following the weekend violence.
"After the January killings, the villages should have been properly protected," U.N. High Commissioner for Human Rights Navi Pillay said. "Clearly, previous efforts to tackle the underlying causes have been inadequate, and in the meantime the wounds have festered and grown deeper."
Human Rights Watch also urged Jonathan to provide protection for those in the small villages surrounding Jos, a central Nigerian city that has become the fault line for religious violence in the region.
Those who survived attacks Sunday in three mostly Christian villages said security forces never provided them any guards, even though Jos itself has remained under a dusk-til-dawn curfew since January's fighting.
"It's time to draw a line in the sand," Human Rights Watch researcher Corinne Dufka said in a statement Tuesday. "The authorities need to protect these communities, bring the perpetrators to book and address the root causes of violence."
Police say they have arrested more than 90 people suspected of inciting the violence. Some described it as a reprisal attack for Muslim deaths in January, while others said Fulani cattlemen wanted to take over land on the dusty plateau.
The U.S. Embassy in Abuja, Nigeria's capital, issued a statement calling on Nigeria's federal government to seek justice "under the rule of law and in a transparent manner," the embassy said.
The U.S. also asked the state government to "to ensure that all people and citizens in the Jos area feel that they are respected and protected."
Jonathan said security forces would lock down the borders of Plateau state to stop weapons and potential fighters from infiltrating the region. But on Monday, an Associated Press reporter passed through seven supposed checkpoints where searches should have been conducted and none were. Some posts were unmanned, while police and soldiers at others merely watched a line of cars pass by without stopping them.
The killings Sunday add to the tally of thousands who have already perished in Africa's most populous country in the last decade due to religious and political frictions. Rioting in September 2001 killed more than 1,000 people. Muslim-Christian battles killed up to 700 people in 2004. And more than 300 residents died during a similar uprising in 2008.
Nigeria is almost evenly split between Muslims in the north and the predominantly Christian south. The recent bloodshed has been happening in central Nigeria, in towns which lie along the country's religious fault line. It is Nigeria's "middle belt," where dozens of ethnic groups vie for control of fertile lands.