Demolition squads of the Municipal Corporation of Delhi on Wednesday targeted 18 properties in four civic zones under its ongoing citywide demolition drive against unauthorised constructions even as residents' welfare associations and some trade organisations organised protests accusing the civic body of adopting a pick-and-choose policy and not taking action against influential people including politicians. Under the new policy adopted due to non-availability of security personnel, the civic body took action in only four zones -- Karol Bagh, Shahdara (North), Shahdara (South) and Sadar Paharganj -- demolishing