The police have sealed the city office of IVRCL Infrastructure -- the implementing agency of Kolkata's Vivekananda Road Flyover, which collapsed on Thursday.
"The office of the construction company here have been sealed and we will take strong action against them,"said Police Commissioner Rajeev Kumar.
Earlier, following instructions from Chief Minister Mamata Banerjee, police had lodged an FIR against the Hyderabad-based company, whose chief termed the mishap as an "act of God".
At least 21 people died and over 70 got injured after the flyover in the congested Posta area of northern Kolkata crashed, crushing scores of unsuspecting people.