NEW : Prince William and Catherine visited Birmingham to meet people affected by the riots . Police say that shots were fired at police and a police officer . Police hope members of the public will help them identify those involved . The violence came amid widespread protests in English cities this year .
NEW : Prince William and Catherine visited Birmingham to meet people affected by the riots . Police say 11 shots were fired at officers and a force helicopter . Police hope members of the public will help them identify those involved . The violence came amid widespread disturbances in English cities this month .