The income tax department's investigation wing on Thursday began search and seizure operations at 24 premises of realtors, including son of former Tamil Nadu governor Surjeet Singh Barnala, and a developer in Chandigarh, Mohali, Panchkula and Zirakpur.The realtor targeted by I-T sleuths was identified as Manohar Singh. One of his business associates is Barnala's son Gaganjeet Singh.N K Saini, director I-T investigations, supervised the searches while joint director Manjit Singh coordinated the operations.