Enforcement Directorate (ED) sleuths on Tuesday conducted simultaneous raids and search operations at various locations in West Bengal in connection with its probe into alleged irregularities in NRI quota admissions in several medical colleges and hospitals, an officer said. The ED officers also raided the residences of officials of those institutions in Kolkata's Salt Lake as well as in the districts of Birbhum, Durgapur, Jhargram and Burdwan, he added. The central probe agency officers seized several documents and bank-related papers from the offices and the residences during the raids, he said. "The officials of the institutions were also questioned regarding the papers and documents seized from their possessions," the ED officer said. Accompanied by a large number of central forces, the ED officers also raided the residence of former CPI(M) leader Lakshman Seth in Haldia and the medical colleges run by his NGO. Similar raids were on at Shantiniketan Medical College and Hospita