Police in northern Nigeria say 19 suspected members of a radical Islamist sect have been killed in clashes with security forces.Yobe state police chief Patrick Egbuniwe said Wednesday that the police and army shot dead two suspected Boko Haram members Tuesday night in the city of Damaturu. He said two civilians also died in the clashes.Kano state police chief Ibrahim Idris said authorities in Nigeria's second-largest city shot dead 17 suspected sect members who launched coordinated attacks targeting police Tuesday night. Idris says one policeman was killed.Meanwhile, Taraba state police spokesman Amos Olaoye said gunmen also attacked police in the town of Wukari, leaving three policemen and two civilians dead Tuesday night.Boko Haram is held responsible for more than 620 deaths this year alone, according to an Associated Press count.