The Income Tax Department on Tuesday raided 20 premises linked to Gitanjali Gems promoter Mehul Choksi and suspected shell firms in connection with an alleged tax evasion case against them, official sources said. They said the searches, launched at about 4pm, were being conducted in Mumbai, Pune, Surat, Hyderabad, Bengaluru and a few other cities against 13 companies linked to Choksi.