Police vehicles were set ablaze at the Charu Market police station after Saturday’s bus mishap. A Telegraph picture

Police have registered a general diary against Trinamul Congress leader Partha Chatterjee, who had allegedly threatened police commissioner Gautam Mohan Chakrabarti after Saturday night’s violence at Charu Market police station.

According to the police chief, Chatterjee had called him on his cellphone and threatened that Bengal would “burn” unless those arrested for the violence were released.

“The entry in the record book will help us if we decide to proceed against Chatterjee,” said an officer of Charu Market police station.

Home secretary Asok Mohan Chakrabarti said the violence had been masterminded by Swarup Biswas, the brother of Trinamul Congress MLA Arup Biswas. “He is absconding. The chief minister has been informed about the incident.”

Asked whether any action would be taken against Chatterjee, the home secretary said: “I will discuss the matter with the police commissioner after Puja.”

A group of youths had barged into Charu Market police station and injured 21 cops, including two deputy commissioners, before setting four vehicles on fire. The police rounded up 29 people.

Minutes later, Trinamul leader Chatterjee called the police chief and said the state would burn if those arrested were not “released immediately”.