NIAMEY — A Niger opposition chief was put back in prison Tuesday after being freed following his arrest for calling for protests against a new constitution extending the president's rule, his organisation said. Earlier in the day, Niger police teargassed a crowd of political figures and human rights activists who had come to attend the trials of the opposition leader and a prominent journalist. "Marou Amadou has just been kidnapped aboard two 4x4 vehicles by members of the Republican Guard at the prison in Niamey as he was trying to complete formalities for his freedom from prison," Ali Idrissa, a...