You have to add rule like this.
'rules'=>array(
'site/index/city/<city:.*?>'=>'site/index',
'<controller:\w+>/<id:\d+>'=>'<controller>/view',
'<controller:\w+>/<action:\w+>/<id:\d+>'=>'<controller>/<action>',
'<controller:\w+>/<action:\w+>'=>'<controller>/<action>',
),