Four persons, stated to be local leaders of the Trinamool Congress, were arrested by the city police here on Saturday in connection with the assault on Ambikesh Mahapatra, a professor of Jadvapur University, on Thursday evening.
The four were produced at a City Court and granted bail.
The arrests came a day after Mr. Mahapatra was arrested on charges of circulating e-mails containing graphics directed at Chief Minister Mamata Banerjee among others. He was subsequently granted bail.
Mr. Mahapatra alleged that a group of youth had assaulted him and forced him to declare that he was a member of the Communist Party of India (Marxist).
They were charged for criminal intimidation, causing hurt and wrongful restraint -- all of which are bailable offences under the Indian Penal Code.
The persons included Amit Sardar who had lodged a complaint against Mr. Mahaptara and his neighbour Subrata Sengupta. The others were identified as Arup Mukherjee, S K Mustafa and Nishikanta Gorai.
Some of the accused were also involved in running a syndicate supplying construction materials.
Mr. Mahapatra had filed a written complaint against the accused at the Purba Jadvapur police station on Friday evening, hours after he was released on bail.
Mr. Mahapatra and his neighbour Mr. Sengupta were arrested Thursday evening and charged with defamation, outraging the modesty of a woman and hacking.
“I had to spend the night in the custody while those who assaulted me were granted bail shortly after they were arrested. I have nothing to say in this regard. People are witness to the developments and they will decide on this,” Mr. Mahaptara said.