In a war against education, the casualties are the young and ambitious.
In northern Nigeria, it has become dangerous to drink in a street bar, play gospel music in a public place or watch televised soccer matches at sports bars and big-screen viewing centers. Roads and bus stations are fraught with risk. But it is schools that have become the front lines of the war to establish an Islamist state, one in which boys' education would be limited to Koranic schools and Islamic universities, and girls would stay home and get married.
On Monday, dozens of students were killed in a suicide bombing at an all-boys high school, the latest in a series of such attacks.
There was global horror in April over the kidnapping of nearly 300 schoolgirls from the northeastern town of Chibok. The abduction prompted First Lady Michelle Obama, among others, to speak out about the risks girls everywhere face for pursuing their ambitions.
But attention on the Chibok girls overlooked a string of attacks on Nigerian boys that began in 2013. Schoolboys and male college students have been locked into dormitories, burned alive, shot in their beds, blown up or had their throats cut — all for seeking an education.
Monday's bombing, in the town of Potiskum in Yobe state, occurred just before 8 a.m. as students gathered at the Government Comprehensive Senior Science Secondary School. The attacker came disguised as a student wearing a school uniform, witnesses said.
The blast killed 48 people, mostly students, said hospital and morgue officials. Two teachers were among the dead, and 79 people were injured, some critically.
In the aftermath, textbooks, shoes and bloodied bodies lay scattered across the site.
"We had gathered in rows at the assembly ground outside the principal's office waiting to be addressed for the morning assembly when we heard a huge explosion from the middle of the rows," said a student, Adamu Ibrahim, 17.
"The explosions flung students at the center of the blast in all directions. It also sent many of us reeling on the ground. I found myself under the weight of another student who fell over me. I'm certain he was dead," he said in a telephone interview.
"It was confusion all over," he said. "Everybody was hysterical."
Another student, Musa Ibrahim Yahaya, 17, described similar mayhem.
"We were waiting for the principal to address us, around 7:30 a.m., when we heard a deafening sound and I was blown off my feet. People started screaming and running. I saw blood all over my body," he told the Associated Press from his hospital bed.
No one claimed responsibility for the attack, but police spokesman Emmanuel Ojukwu said authorities blamed Boko Haram, an extremist Islamist militia that has been fighting to impose an Islamist state in Nigeria. The group is bitterly opposed to the government and to anything identified with Western culture, including secular education, taxes and democracy.
Boko Haram, a nickname used by locals to describe the group, means "Western education is a sin."
After the bombing, Adamu said, he and other students with relatively minor injuries ran home.
"When my father, who was sitting outside the house, saw me, he was terrified," Adamu said. "I didn't realize my white school uniform was stained with human blood and bits of flesh. I'm all right, except for the pains in my ears from the thunderous blast. My ears hurt and a humming sound persists inside."
He said the school was poorly secured, with no fence, making it an easy target.
A spokesman for the Nigeria Security and Civil Defense Corps, which helped evacuate the victims, said most of the injured had serious burns and blast wounds.
The injured were sent to Potiskum General Hospital, about 100 yards from the school, where they had to be squeezed in, two to a bed.
Since 2013, attacks in Yobe state, in Nigeria's troubled northeast, have targeted students and teachers, sometimes killing dozens at a time.
Education levels in northern Nigeria are lower than in other parts of the country, and state governments have been forced to close schools in some areas because of frequent terrorist attacks. Only 28% of children in the northern state of Borno attend school, according to government statistics, and the literacy rate in the north is 32%, compared with the 68% national average.
Both male and female students have been targeted, but whereas boys tend to be killed, girls are often abducted as sex slaves. In the northeast, extremists have abducted hundreds of women and girls.
Boko Haram's leader, Abubakar Shekau, and fighters who have attacked schools have spelled out the group's ideology: Girls shouldn't go to school or work but should stay home, get married and have children. Shekau has called the Chibok girls "slaves," who he said were sold.
Boys seeking a Western-style secular education are reviled by the Islamists.
Last month, authorities claimed to have reached a cease-fire deal with Boko Haram, but attacks and abductions have continued. Amid reports in recent weeks that the Chibok girls might be freed, a video purporting to be from Shekau repudiated any deal and said the girls had been married off to fighters. The authenticity of the video hasn't been established.
According to Human Rights Watch, at least 500 girls in northern Nigeria have been abducted. Thousands of people in the north have been killed by Boko Haram since 2009, including hundreds of students and teachers.
Boko Haram emerged about a decade ago, but it has stepped up its attacks in recent years. Nigeria's military, often accused of fleeing attacks or abandoning its posts, has been criticized for failing to halt the insurgency.
In June 2013, gunmen believed to be from Boko Haram invaded a government high school in Damaturu, capital of Yobe state, shooting eight boys and a teacher in the dining room. A month later, gunmen attacked a boys' boarding school in Yobe's Mamudo village, killing 42 people. The victims were shot to death or burned alive in their dormitories.
In September last year, gunmen invaded a dormitory at an agricultural college in the Gujba district of Yobe state in the early-morning hours and shot dozens of students in their beds, killing at least 42.
In February, gunmen attacked a school in Buni Yadi, also in Yobe state. They sent female students away before killing 59 boys, primarily using gasoline bombs and gunfire. Some students had their throats cut as they tried to flee.
Last week, 30 people died in a suicide attack on a Shiite Muslim religious procession in Potiskum.