Nigeria's acting president put security forces on alert after machete wielding gangs massacred at least 100 people, mainly women and children, near the central city of Jos, officials said.
Witnesses described how victims were caught in animal traps and fishing nets as they tried to flee their attackers, who hacked them to death in what appeared to have been a well-organised attack.
"Over a hundred people have been killed -- most of them women and children," said a government official Sunday, speaking on condition of anonymity.
"Some of the children are less than one year old," he added.
|File photo shows residents carrying possessions past a burnt building following violent clashes in the town of Kuru Karama, 30 kilometres from Jos.|
Much of the violence in the early hours of Sunday was centred around the village of Dogo Nahawa, near the Jos, where a journalist counted a total of 103 bodies amid the smouldering embers.
But the raiders also set fire to dozens of houses in the nearby villages of Ratsat and Zot, all less than 10 kilometres (seven miles) from Jos and home to members of the Berom ethnic group.
"These villages were attacked by Fulani herdsmen killing scores of people and burning houses," Ratsat resident David Daniel Daniel told AFP.
Other residents and local rights activists also blamed the attacks on the Fulani ethnic group.
In Jos, Yusuf Alkali, a member of the Fulani ethic group, said he believed the attacks were a reprisal for the killings of four herdsmen two weeks ago when a Fulani settlement was attacked by ethnic Berom youths.
Officials displayed another 18 bodies at the morgue in Jos -- the scene of inter-religious riots in January that left several hundred people dead.
Acting President Goodluck Jonathan "has placed all the security services in Plateau (State) and neighbouring states on red alert so as to stem any cross border dimensions to this latest conflict," his office said in a statement.
"He has also directed that the security services undertake strategic initiatives to confront and defeat these roving bands of killers," it added.
Dan Manjang, an advisor to the Plateau state government confirmed that troops had been deployed to the area.
But traumatised residents accused local officials of having turned a blind eye to the bloodshed.
"The operation started around 3:00 am (0200 GMT) and lasted till 6:00 am and there were gunshots, but we did not see a single policeman," Peter Gyang, who lost his wife and two children, told reporters in Dogo Nahawa.
"We no longer have confidence in the security agencies."
Many of the victims had been hacked to death as they tried to run for their lives, he added.
"Gunshots were fired just to scare people out of their houses only to be macheted as they fled into the bush," he said.
"It seems the attacks were well coordinated as the attackers launched ... (them) simultaneously," Shamaki Gad Peter, head of League for Human Rights in Jos, told AFP as he toured Ratsat village.
"At the moment, there are about 100 dead bodies. From what I see, the scale of destruction is enormous."
Houses and food granaries were still smouldering more than 12 hours after the attacks, which happened in the small hours of Sunday.
Shehu Sani, a local rights activist said some fleeing residents were caught in animal traps and fishing nets set by the suspected Fulanis.
Parts of Jos and its environs are still under a dusk-to-dawn curfew since the January religious clashes.
This central region of Nigeria had been a regular ethnic and religious flashpoint.
An explosion of violence between rival ethic and religious groups in January left 326 dead in Jos, according to police although other human rights activiets put the overall toll at more than 550.
In November 2008, the federal government sent in the troops after Christians and Muslims fought each other using firearms and machetes in clashes that followed a contested election in Jos.
Official figures put the death toll at 200, but rights groups Human Rights Watch said it the dead number more than 700.