Gunmen killed 21 people including many high school students and wounded one on Sunday after dragging passengers off buses northeast of Baghdad, officials said. Four Sunni Arabs on board were spared and the dead were all either Shiites or Kurds. Serwan Shokir, the mayor Qara Tappah, said the incident occurred in the early morning after three mini buses left his town headed for Baqouba - located 60 kilometers northeast of Baghdad. He said the gunmen dragged 26 people from the buses, separated four Sunni Arabs who were in the group, and shot all the rest. Shokir said 12 of the dead were high school student and of those killed, 19 Shi'ite Turkomen and two were Kurds. The students were headed to another town to take exams.