India, Nov. 11 -- A day after hundreds of people staged protests against rising air pollution and the recent Supreme Court's ruling on stray dogs at India Gate, the Delhi Police filed an FIR against unknown persons for "violating" police orders and disturbing law and order, officials said.

According to police, on Saturday-a day before the protest-additional DCP Anand Kumar Mishra wrote to the protesters, directing them to shift the demonstration to Jantar Mantar due to security and traffic reasons at India Gate.

However, on Sunday evening, several environmentalists and animal rights activists gathered at India Gate. Heavy police forces were deployed, and soon clashes broke out after police started detaining them.

Devesh Kumar Mahla, DC...