(GIN)—As Americans honored their veterans in a national day of parades and ceremony, Nigerians were grieving over a war with terrorists, who are now slaughtering children with suicide bombs.

Schools have become the frontlines of the war waged by Boko Haram against Nigerian security forces. As Boko Haram occupies more villages in the country’s north, they claim to be building 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.

Monday, in the town of Potiskum in Yobe State, students were lining up at the all-boys Government Comprehensive Senior Science Secondary School. The attacker was disguised as a student in a school uniform.

The blast, set off when the youthful bomber was questioned by a teacher, killed 48 people, mostly young children, according to hospital and morgue officials. Two teachers were among the dead, and 79 were injured, some critically.

This bombing was only the latest in a series, however, of attacks on schoolboys and male college students that began in 2013. Newspaper accounts of a massacre in Yobe state told of students locked in their dormitories and burned alive, shot in their beds, blown up or having their throats cut.

“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,” Musa Ibrahim Yahaya, 17, told the Associated Press from his hospital bed. “People started screaming and running. I saw blood all over my body.”

“The explosions flung students at the center of the blast in all directions,” said another student in a telephone interview. “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.”

“It was confusion all over,” he said. “Everybody was hysterical.”

After the bombing, Adamu Ibrahim said he and other students with minor injuries ran home.

“When my father, who was sitting outside the house, saw me, he was terrified,” Ibrahim 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.

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 percent of children in the northern state of Borno attend school, according to government statistics, and the literacy rate in the north is 32 percent, compared with the 68 percent national average.

Meanwhile, the U.S. came in for blistering criticism from Nigeria’s ambassador to the U.S., who condemned Washington for refusing to sell his government “lethal” weapons to fight militant Islamists.

Nigeria needed support to deliver the “killer punch,” not “light jabs,” against the Boko Haram group, Adebowale Ibidapo Adefuye told members of the Washington-based Council on Foreign Relations.

U.S. laws ban the sale of lethal weapons to countries whose military are accused of gross human rights abuses, and Nigeria’s government soldiers have been accused by rights groups of carrying out many atrocities, including torturing and executing suspects.