LAGOS, Nigeria (AP) -- The pastor would not renounce his Christian faith so the Islamic extremists slit his throat.
High school students were taking exams in defiance of the militants of Boko Haram, whose name means "Western education is forbidden." So the gunmen mowed them down at their desks.
The group that Nigeria's government has declared a prohibited terrorist organization "declared war" last week on vigilante youths who have been arresting suspects and handing them over to soldiers fighting to crush the insurgency in the northeast part of Africa's most populous nation and the continent's biggest oil producer.
The radical group that once attacked only government institutions and security forces is increasingly targeting civilians. Some 155,000 square kilometers (60,000 square miles) of Nigeria are now under a state of emergency.
"Today, there are no boundaries and they are targeting the civilian population in a way that shows Nigeria is at a dangerous turning point," said Comfort Ero, Africa program director for the International Crisis Group.
A month-long military crackdown by a joint force of troops and police, including bombing raids with fighter jets and helicopter gunships, has broken up militant camps but succeeded only in chasing the fighters into scrubby mountains from which they launch attacks on cities and towns, under the noses of the soldiers.
The government has described the change in tactics as an "end-game strategy" of a movement near collapse. But recent attacks indicate otherwise.
In broad daylight two weeks ago, militants sneaked into Maiduguri, capital of Borno state, and attacked students at Ansarudeen Private School as they were taking exams. Nine students were killed, according to Dr. Salem Umar of the General Hospital, who received the bodies in school uniforms. He said six other students were admitted with gunshot wounds.
That attack came hours after extremists attacked the Government Secondary School, a boarding school for seniors in Damaturu, capital of Yobe state, killing seven high school seniors and two teachers. The military said two soldiers and two jihadists also were killed in what developed into a five-hour shootout.
"They caught some of our student colleagues and ordered them to take them to the teachers' quarters, after which they were also killed," said a traumatized student who survived by hiding under his bed in a dormitory, for hours. He asked that his name not be used, fearing he would be targeted by the extremists.
On Friday, villagers streamed into Maiduguri from the Gwoza hills, saying Boko Haram fighters were threatening a bloodbath in the area where they appear to have regrouped, scrubby mountains with rock caves some 150 kilometers (90 miles) from the city.
Nigeria's government first sought to crush Boko Haram in punishing raids in 2009 on the sect's Maiduguri headquarters in which nearly 200 people were killed by security forces. The group was blamed for the killings of hundreds more civilians. The founding leader of Boko Haram, Mohammed Yusuf, was captured, then shot in the back by police who claimed he was trying to escape.
So it's not surprising that Boko Haram militants are not responding to a government offer of amnesty.
The group re-emerged in attacks on government institutions and especially the police, whom they accuse of executing Yusuf. Boko Haram is blamed for the killings of more than 1,600 people since 2010 alone, according to an AP count.
The World Policy Institute said this month that Boko Haram is funded by criminal activities including bank robberies, money from politicians, and contributions of money and arms from al-Qaida affiliates in Africa.
Nigeria's politicians have traditionally exploited explosive religious differences, and they have been publicly accusing each other of funding Boko Haram.
The movement appears to have little difficulty finding recruits among the plentiful unemployed and disgruntled youth as it seeks to create an Islamic state in northern Nigeria, where a moderate version of Sharia law already is in place.
The renewed violence already has forced more than 6,000 people to flee to the neighboring country of Niger while some 3,000 others went to Cameroon, the United Nations has reported.
Those who remain say they are terrified of both sides, with the country's notoriously trigger-happy soldiers accused of killing dozens of innocents in the clampdown. The military denies charges by rights groups that it is responsible for gross human rights violations.
Sandbags, armored personnel carriers and military trucks loaded with soldiers bristling with guns and grenade launchers are a common sight. Tanks hide under trees on the outskirts. At checkpoints, dozens of cars line up, waiting to move out under a military escorts under the protection of gunners constantly swiveling their weapons atop personnel carriers.