The areas where the Building Department-I and II of the Civil Lines Zone of the NDMC has taken actions include Ashok Vihar, Kamla Nagar, Rani Bagh and Mukherjee Nagar.
In Tri Nagar, roof of a building's second floor was partly demolished, while in Kewal Park shuttering was demolished and reinforcement removed from the second floor of another property, which was under construction.
"The demolition action has been taken in the last few weeks or so. We are quite keen on removing unauthorised constructions, and so our efforts would continue," a senior NDMC official said.