Early Sunday morning as villagers prayed, men in camouflage crept into a local mosque and opened fire, killing at least 44 worshipers and sending dozens of others to the hospital, according to local security sources. Some 20 miles away, 12 other people were killed in a similar attack.
Nigerian authorities are now publicly blaming Boko Haram for the attacks in the villages of Konduga and Ngom, and saying that the Islamist militant group was sending a message: If you cooperate with Nigerian security forces, we may kill you.
The attacks were the latest in a series of massacres associated with the Nigerian radical group that has, since mid-May, come under a full military crackdown in the north, escalating what some analysts say is a strategic back and forth between the radicals and the government.
The Nigerian Army claims to have killed or arrested hundreds of Boko Haram members since May. Last month the group was charged with the burning of a school that took the lives of 29 to 40 persons, most of them children.
Moreover, this week Boko Haram's ostensible leader, the shadowy Abubakar Shekau, who appears only on videotape, challenged a variety of world leaders, including US President Obama, saying "you are no match for me."
While the group started out with an anti-Western, anti-Christian message (the term "Boko Haram" translates as "Western education is sinful") its core ideology appears increasingly inchoate even as its targets of killing get wider and wider, this time including Muslims praying in a mosque.
One reason given for Sunday's mosque attack is that clerics there were putting out a moderate message of greater harmony among peoples, rather than preaching adherence to the Boko Haram version of strict sharia law, analysts say.
“It seems most often [that] whoever crosses the group is a potential target,” according to Elizabeth Donnelly of the Africa Program at the London-based think tank Chatham House. “You’re either on our side or you’re a potential victim.”
Rather than targeting Christians strictly for their faith, she adds, Boko Haram has used existing tensions between Muslims and Christians to increase the chaos in Nigeria’s north.
Nigeria is roughly divided between Muslims in the north and Christians in the south.
Human Rights Watch says that this kind of community violence – not related solely to issues of faith, but between self-identifying Muslims and Christians groups – has been responsible for the lives of some 14,000 Nigerians since 1999, well before Boko Haram began to operate.
Officials from Borno state where the attack on the mosque took place said it was likely aimed at scaring informants that are helping in the military campaign against Boko Haram.
Since Nigerian President Goodluck Jonathan declared in May a state of emergency in the northeastern Borno, Adamawa, and Yobe states, the military has been relying on public participation to counter the group.
In a video released shortly after the mosque attack, Abubakar Shekau claims his group is not only successfully taking the fight to Nigeria, but is ready to battle nations around the world.
“We have killed countless soldiers and we are going to kill more,” Mr. Shekau says on the video in his native Hausa language. “Our strength and firepower has surpassed that of Nigeria…. We can now comfortably confront the United States of America.”
Boko Haram is blamed for between 1,000 and 2,000 deaths since it began operating in 2009. It has attacked schools, churches, markets, communications networks, and government buildings.
Nearly all attacks were confined to Nigeria’s arid north, which is suffering from lack of development, widespread poverty, and unemployment.
Reuters has recently quoted Nobel Prize-winning Nigerian author Wole Soyinka saying that some politicians in the north of Nigeria "conjured up a Frankenstein" by initially supporting the group.
Boko Haram’s real strength, according to Ms. Donnelly of Chatham House, is its ability to stay alive by constantly switching tactics.
“Boko Haram has kept evolving and changing,” she says. “It’s constantly adapting to the security environment.”
Sunday's attacks occurred 25 miles outside Maiduguri, the epicenter of the Boko Haram insurgency, and a town that had been the group’s original home base.
Civilian vigilante groups opposed to Boko Haram have recently formed in Maiduguri with the support of the Nigerian Army.
One vigilante, Usman Musa, told reporters on Monday in Maiduguri that his group traveled about 20 miles to Konduga where they fought with heavily armed militants. He said four of his comrades were killed.
“I don't know about the soldiers,” he added. “But it was a very bad incident.”