MAIDUGURI — The governor of Nigeria's northeast Yobe state is ordering all schools closed to avoid attacks by militants who have killed dozens of students and teachers. The UN children's agency, meanwhile, said Monday that 48 students and seven teachers have been slain since June in northeast Nigeria. “There can be no justification for the deliberate targeting of children and those looking after them,” said UNICEF regional director Manuel Fontaine. Gov. Ibrahim Gaidam issued the order after visiting students with burn and gunshot wounds from Saturday's attack on a boarding school outside Potiskum, the state's second largest town. Extremists set a dormitory ablaze, burning some students alive. At least 29 students and one teacher were killed. Last month Islamic fighters attacked at least two schools, killing 16 students and two teachers. Gaidam said such attacks could be averted if the military would resume cell phone service cut to three northeastern states since the government declared a state of emergency May 14. He said residents could have alerted the military by cell phone. Authorities have blamed the spate of recent attacks on Boko Haram, a terrorist group whose name means “Western education is sacrilege.” The group and its offshoots have killed more than 1,600 civilians in a series of suicide bombings and other attacks since 2010, according to an Associated Press count. The group's stronghold is Maiduguri. It is also believed to have a strong network in Adamawa state, prompting President Goodluck Jonathan to deploy thousands of troops to regain control of the region. —AP