"Security in-charge of ESIC Medical College, Nerchowk, approached the police after finding the slogans on the walls and police registered a case under Sections 124 A, 153 A of IPC," said ADGP (Law and Order) Sanjay Kundu said.
During the course of investigation, about 80 labourers have been interrogated so far and forensic evidence has been collected and further investigation is in progress, he said.