Boko Haram is singling out geography teachers in its campaign of terror against Western education in Nigeria, it has been revealed.
Teachers of the subject have emerged as an unlikely top target for the group because their lessons contradict its bizarre world view on how the Earth was created.
Boko Haram believes that the Earth is flat rather than spherical, and that rainfall is caused not by evaporation, but by God's divine will.
As such, geography teachers are ranked alongside Nigerian security chiefs and senior politicians as prime candidates for assassination.
The threats to geographers are outlined in an extensive new report by Human Rights Watch, which lays bare the devastating impact wreaked by Boko Haram on Nigeria's school system.
It says that a total of 600 school staff have been murdered by Boko Haram since 2009, and that 19,000 have quit their jobs due to threats and attacks.
The report is timed to coincide with this Thursday's two-year anniversary of Boko Haram's kidnapping of more than 200 schoolgirls from the town of Chibok in Borno state in northeast Nigeria. They remain as hostages to this day.
The report says that in Borno, Boko Haram's main stronghold, schooling in 22 out of 27 local government areas has been closed down, depriving hundreds of thousands of children of the right to learn.
"In its brutal crusade against Western-style education, Boko Haram is robbing an entire generation of children in northeast Nigeria of their education," said Mausi Segun, Human Rights Watch's Nigeria researcher.
The 86-page report, based on interviews with more than 200 teachers, students, parents and school officials, documents numerous attacks on schools by Boko Haram gunmen, some of which ended in abductions and some of which ended in massacres.
It notes: "Boko Haram insurgents have shown particular distaste for certain subjects like geography and science ... Teachers of these subjects are targeted."