The income tax department on Tuesday raided 33 locations in Tamil Nadu belonging to major business groups. The raided premises include those owned by the construction and engineering firms Patel Group, Marg Group, Milan Group and Ganga Foundations Group, ANI reported.

It is unclear whether the raids are related to the searches earlier this month at locations connected with ousted All India Anna Dravida Munnetra Kazhagam leader VK Sasikala. An official told IANS it was a follow-up to earlier raids, but another told The Hindu they were not connected.

The raids are in relation to a crackdown on shell companies, The Hindu reported.

Search operations are under way at the 21 premises in Chennai and 12 outside the city.

More details are awaited.