Mumbai Riots
Policemen stand near a burnt vehicle after a protest turned violent in MumbaiReuters

Mumbai police are suspecting Saturday's violence at Azad Maidan as a "pre-planned" act, and arrested 23 people in connection to the riots, which led to the deaths of two people in the rally against communal killings in Assam.

Shortly after the crowds dispersed from the grounds, authorities recovered sticks, rods, stones and inflammable material in cans, leading authorities to believe that violence was a pre-meditated attack. 

Police have also made a distinction in the participants at the protest venue, with CCTV footage showing a mob armed with sticks boarding a train at Kurla railway station and getting down at Chhatrapati Shivaji Terminus before heading to Azad Maidan in South Mumbai.

Few police weapons were reported stolen and many woman participants in the rally including female constables were allegedly molested by the mob. Several vehicles were torched and the Amar Jawan memorial was vandalized at the time of the attacks, reports said.

According to the Indian Express, police were given a prior warning of possible attacks in an intelligence report that cited "law-and-order problems", "charged atmosphere" and a population of "10,000 with an upward bias". 

Violence at the rally reportedly began around 3 pm after organizers made an inflammatory speech. "The Crime Branch would also probe if any inflammatory speech was made by the organisers of the protest rally, where 17 people were present on the stage and five others had addressed the gathering before the violence broke out. We will study their speech," an official said to the Associated Press.

The outbreak of violence pressed the police to open fire in a bid to disperse the crowds. Around 55 people were injured in the clashes.

The protest was initiated by secular outfit Raza Academy to condemn Muslim killings in Assam and Myanmar.  The group, who offered an apology for the Saturday's riots, denounced the violence as the work of a Muslim.

"This was a planned attack by non-Muslims who want to create a rift between the media and Muslims as the people who started the violence did not belong to our academy," a spokesperson said according to the Indian Express.

Meanwhile, the Mumbai Crime Branch, which is leading the investigations, has charged the accused for rioting, murder, and damaging public property. The suspects will remain in custody till Aug 19.