Four people, believed to be TMC workers, have been arrested by the Kolkata Police in connection with the assault on Jadavpur University professor Ambikesh Mahapatra.
Professor Mahapatra was assaulted on April 12 after he posted anti-Mamata Banerjee cartoons on social networking sites.
Sheikh Mustafa, Nishakanta Gharai, Amit Sardar and Arup Mukherjee were arrested after the professor filed FIR against people who beat him up.
The police arrested the professor for sharing anti-Mamata cartoons on social networking websites and produced in an Alipore court on Friday.
He was released on bail, after a written statement- which the professor said was forced to write that he was an active member of the CPM. The professor also told the police that he fears for his life.
Mr Mahapatra shared the cartoon with few of his friends. Within hours it was being shared across social networking websites with many slamming Mamata Banerjee on Twitter for the professor's arrest.