MAIDUGURI, Nigeria: Suspected Islamist extremists have attacked a secondary school and military checkpoint in Nigeria’s northeast, leaving 11 people dead including seven students, the military said on Monday. Details were sketchy and the information could not be independently confirmed. Mobile phone lines have been cut in much of the northeast since the start of a military offensive targeting Islamist extremist group Boko Haram on May 15 and access to the area is limited. The attackers were said to have stormed student living quarters on Sunday night in the city of Damaturu and shot sporadically, killing seven students and two teachers. Two insurgents were also killed, the military said.