The CPI-M on Wednesday expressed "grave concern" over the growing signs of hatred and use of violence to intimidate groups and individuals who hold views contrary to those of the perpetrators.
"Particularly disturbing is the inaction, complicity and failure to apprehend the perpetrators by the law enforcement agencies," the Communist Party of India-Marxist said in a statement.
"It is also clear that such brazen acts which show utter disregard for laws of the land could not be spreading rapidly but for this complicit role," it said.
"No doubt, the overall atmosphere in the country which smacks of intolerance, hatred and polarization has apparently emboldened the perpetrators."
The CPI-M urged Prime Minister Narendra Modi, "who recently claimed that he is the PM of the whole country and not just of the BJP, to come out categorically and initiate measures to stop such blatant violations of law and the constitutional principles.
"Citizens must be emphatically reassured, constitutionally will not be allowed to be breached."
The CPI-M denounced the acid attack on social activist-turned-AAP functionary Soni Sori in Dantewada district in Chhattisgarh. Sori is now in Delhi seeking urgent medical attention.
It expressed outrage over the way "an extreme rightwing group" forced a policeman, Yusuf Sheikh, in Latur in Maharashtra to be paraded and install a saffron flag.
The CPI-M said similar violence was let loose on JNU student leader Kanhaiya Kumar, academics and journalists while he was in police custody and in the Sessions Court in the Patiala House Court in Delhi.
