Delhi Police's probe into the unprecedented violence during a tractor rally by farmers on Republic day is now focused on finding those involved in planting a Sikh religious flag at the Mughal-era Red Fort. Tuesday's tractor rally went rogue as protesters forced their way inside the fort complex placed a flag. Several teams of Delhi Police's special cell or anti-terror unit are scanning through footage of violence at the iconic fort complex to identify those who hoisted the flag there. Actor-activist Deep Sidhu, whom farmers have accused of being responsible for the unprecedented violence during the Republic Day tractor rally, has been named in a case filed by the Delhi Police, sources told NDTV. A handful of farmer leaders have also been named in the 25-plus cases filed by the police since Tuesday evening. 19 people have been arrested in connection with the violence in which 394 police personnel have been injured, the Delhi Police said.