Police probing Monday’s vandalism by alleged ISF supporters in Bhangar’s Sonpur area said they suspected a “larger conspiracy” as at least 50 CCTV cameras had either been damaged or repositioned before the violence.

Nine ISF supporters have been arrested so far — eight from Uttar Kashipur and one from Chandaneshwar — for the violence that saw five motorcycles set alight and a prison van ransacked. The investigators are hunting for more suspects, with five cases registered so far. At least 16 police personnel were injured, mostly by stone pelting, on Monday.

Damaged CCTV cameras made it difficult for the police to identify the perpetrators of the violence. Bhangar, plagued by recurring violence, was recently brought under Kolkata Police’s jurisdiction, with multiple cameras installed to bolster security. Yet, criminals disabled many cameras, suggesting premeditation. Dome cameras had been turned upward to avoid recording.

“This mirrors the violence in Suti, Dhulian and Samserganj in Murshidabad,” a police officer said.

“Cameras were tampered with meticulously to destroy evidence. It’s a typical conspiracy.

Another police officer called the breach “shocking,” questioning how culprits sabotaged cameras despite police presence.

“Several CCTV cameras were damaged or repositioned, apparently in a well-planned manner so that recording of evidence could be averted and identifying the persons involved in the violence could not be possible in any way,” said the officer.

Police sources said two types of CCTV cameras were installed at Sonpur. One was immovable with a fixed focus, and the other was dome-type CCTV cameras.

The administration was wondering how the cameras had been damaged despite the presence of police. “This is a very shocking outcome indeed”, a senior police officer monitoring the case said.

ISF chairman Nawsad Siddique accused the Trinamool Congress of framing his party in the violence.

“I demand an independent probe. Those who attacked cops might have been ruling party plants or hired by them. I urge police to release images of those who tampered with the cameras. If ISF members are guilty, punish them. But I suspect a larger conspiracy to malign and weaken the ISF,” Siddique told The Telegraph.

Trinamool leader Saokat Molla, in charge of Bhangar, said: “ISF is a party of hooligans, and everyone has witnessed who unleashed violence on Monday. Police will not spare anyone involved in the attack.”

Sonpur had witnessed violence from Monday morning when the police began stopping vehicles carrying ISF supporters on their way to Calcutta to join a march against the amended waqf law.