new delhi civic authorities today demolished portions of 30 buildings in the capital and filed a case against a builder in south delhi during a special drive against illegal construction the action was carried out by the building departments of south east and north delhi municipal corporations the south delhi municipal corporation demolished four properties two properties in chhatarpur and one property each in chirag delhi and masjid moth in chhatarpur demolition action was taken at the buildings where the builder carried out huge unauthorised construction after tampering with the seal affixed by the department an fir has already been registered against the builder for tampering with the seal affixed by the department prosecution action has also been initiated by the department for arresting the builder a spokesperson said the department has so far lodged 35 firs for arresting the builders carrying out unauthorised construction in the area in other localities east and north delhi municipal corporations demolished 26 properties