Screengrab from video of people chanting slogans, dancing and clanging utensils during the curfew.
A group of 40 people was booked in Khadia in Gujarat's Ahmedabad city for gathering at 5pm on Sunday to pay tribute to frontline staff in the fight against the novel coronavirus outbreak.
A video of people chanting slogans, dancing and clanging utensils during the Janata curfew, which was called as a social distancing measure, had gone viral after which a police case was registered, an official said.
Police commissioner Ashish Bhatia said a case was filed against 40 people at Khadia police station under section 188 of the IPC (disobedience of an order duly promulgated by a public servant) and section 3 of the Epidemic Diseases Act, 1897.
"As long as lockdown continues, people should not come out of their homes, and if they do, they should not number more than four in a group. Three FIR have also been registered against people who returned from abroad and were found flouting quarantine rules," he said.
The cases were lodged in Ghatlodia, Maninagar and Odhav, he added.
The police are surveying houses to ensure no one is breaking the 14-day mandatory isolation rule, the police official said.