(AGI) Maiduguri (Nigeria), July 18 - Boko Haram extremistsattacked the city of Damboa in the north-eastern Nigerian stateof Borno, blowing up houses and ruthlessly killing numerouscivilians who had surrendered. The news was reported by localauthorities. "The city was attacked at dawn and many peoplewere killed", an official source stated. The Nigerian army hadattempted to retake the city last week, but was repelled. . .