Police in the northern German city of Hamburg said an hours-long search at a secondary school that went into lockdown over a possible armed youth had turned up nothing suspicious. Students and teachers that had been confined to their classroom during the major police operation were allowed to go home. Police said they found no weapons or other suspicious activity but would carry out another search once the students had left. Officers had descended on the site around noon (1100 GMT) after reports came in that gunman had been seen entering Otto Hahn School or walking past its buildings. The scho…