Any city council member in a city under the city manager plan of government to be elected from a ward, or an appointed successor in the event of a vacancy, shall be a resident and a registered voter of such ward. The city council member shall be nominated and elected in the same manner as provided for at-large candidates, except that only residents and registered voters of the ward may participate in the signing of nomination petitions. All nominating petitions and ballots shall clearly identify the ward from which such person shall be a candidate. The ballots within a ward shall not contain the names of ward candidates from other wards.