The youngest victim of the massacre was a baby, villagers said, born just a couple of hours before the attack on Kuru Karama.

There was not much warning that January morning, only the call to prayer ringing out at the wrong time, 10 a.m., a sure sign of trouble. The town had been surrounded by mobs of Christian men, who, residents said, were seeking to slaughter as many Muslims as possible. Police said 326 people were killed in the attack on the village near Jos in central Nigeria.

Last week it was the other way around: waves of pitiless hacking by Muslim Fulani herdsmen who stormed Christian villages outside Jos, trapping victims in animal nets, leaving 106 dead, police said.

Acting President Goodluck Jonathan launched an investigation of the new violence. Several previous government inquiries have resulted in recommendations that were ignored, according to international and Nigerian rights organizations.

Outrage in Nigeria over the recent massacres of Christians was in sharp contrast to the muted response after the deadly attacks on Muslims in January. The recent reaction appeared to be fed by the inflation of the casualty figures by the Jos government, which is made up of Christians. It said more than 500 people had died.

The ruthless, indiscriminate manner of the attacks in January and this month suggests that reprisals are likely, analysts say.

Nigeria is deeply divided along religious and ethnic lines, and volatile Plateau state, of which Jos is the capital, lies at the crossroads of the largely Muslim north and mainly Christian south.

Tensions between the two sparked a recent political crisis in Nigeria, as southerners in the ruling People’s Democratic Party sought to impeach the seriously ill president, Umaru Yar’Adua, who is a Muslim from the north. Rumors of a coup and attempts to install a Christian president were undercut when Yar’Adua returned after months of medical treatment abroad and the PDP leadership decided that the north should retain the presidency until 2015.

There is deep resentment between indigenous Christian Beroms and Muslim Hausas, who settled Jos after the turn of the 20th century. The involvement of the nomadic Fulani herdsmen, who carried out the recent attacks, is outside the norm. The Fulani attacks appeared to be revenge after the theft of about 200 head of cattle a week earlier.

About 13,500 people have died in Plateau state violence since the end of military rule in 1999, according to Human Rights Watch.

A stray word, misinterpreted; a hissed insult; an argument; a refusal to back off in a showdown -- that’s all it takes in Jos to spark ethnic-religious violence that can leave hundreds dead.

These days, cellphone text messages spread toxic rumors. Young men run for their machetes or guns with murder in their hearts.

Government inaction at the federal and state levels is partly to blame for the recurrent attacks, critics say. At the heart of the Plateau state violence is the question of who is an indigene -- a descendant of the area’s original inhabitants.

The Nigerian Constitution enshrines rights to government jobs and benefits and scholarships to indigenes. The term excludes most Muslim Hausas in Jos because most of their ancestors migrated from the north and settled in Jos early in the last century after British colonizers started mining tin in the area.

They flourished as traders while the Christian Beroms, peasant farmers, missed out on the boom.

Although only the Beroms qualify for indigene rights, most live in dire poverty and resent the Hausa dominance of trade and business. Yet the Hausa resent the fact that they aren’t allowed to work in government and their children can’t win scholarships.

“The government should . . . take concrete steps to end the discriminatory policies that treat certain groups as second-class citizens and that lie at the root of much of the inter-communal violence in Nigeria,” Corinne Dufka, a Human Rights Watch expert on West Africa, said in a January statement. “Nigeria needs to act now to end discriminatory policies and hold accountable those who commit these terrible acts of violence.”

Other analysts concur.

“The federal government has an obligation . . . to deal with violence by the full rigor of the law, but it also needs to look deeper into the circumstances that give rise to so much trouble,” said a 2006 report by the International Crisis Group, calling on Nigeria to “replace the anachronistic concept of indigeneity with a residence test.”

Until this year, large-scale violence usually involved battles between rival mobs. But the attacks on Kuru Karama and other villages in January and Dogo Nahawa, Zot and Ratsat last week were carefully coordinated simultaneous rampages in several villages. Most victims -- the elderly, women and children -- were hacked or shot, and then their bodies and houses burned. In Kuru Karama, dozens of bodies were stuffed down wells.

Two days after the January attack, the ruins still smoldered. The town was deserted but for chickens, bleating goats and a mewing kitten with burned paws, according to a witness.

Masud Saidu, 19, rushed with other youths to the mosque to try to defend the village when the call to prayer sounded and the Christian mobs attacked with guns. He left three brothers to protect his father. All were killed.

“People who tried to get away were run down in the bush and killed. Only the agile, those who could outrun the attackers, escaped,” he said in an interview.

Armed with bows and arrows, the defenders in the mosque had no chance and they fled.

“I was thinking I was going to die,” Saidu said. “My whole mind was focused on how to escape. I was running as fast as I could. And I kept thinking of people I knew who’d been killed and all the property I’d left in my house to be burned.”

Village chief Malam Umar Baza, 46, said the attackers burned his house. “They came from every corner, every entrance to the village, from the bush.”

He jumped into a shallow dry well and hid while his wife and six children were slaughtered, the youngest, a 2-year-old.

Earlier that morning, his wife had dropped by the house of a neighbor, a woman in labor, to help her deliver her baby. The mother and child were both killed.

Shamaki Gad Peter, director of the League for Human Rights in Jos, blames the government for a failure to jail killers in previous attacks and to act on the findings of successive inquiries.

“We are tired of commissions of inquiry,” he said. “What we want now is implementation.”

robyn.dixon@latimes.com