Two people were killed when a group of persons, claiming to be supporters of Dravida Munnetra Kazhagam leader M K Azhagiri, set fire to the Madurai office of Tamil daily Dinakaran on Wednesday morning.
They were protesting a survey that the newspaper published on the ideal political heir to Chief Minister M Karunanidhi.
The two employees who were killed were identified as Gopi, 30, and Vinod, 23, both attached to the administrative wing of the newspaper, the police said.
The protestors also burnt newspaper copies and indulged in protests in various Southern districts of Tamil Nadu.
The survey, which was conducted in association with A C Nielsen, had given 70 per cent chances to M K Stalin, the second son of Karunanidhi, and just two per cent to elder son Azhagiri, who controlled the party cadres in Southern districts.
The protestors also broke the glass panels of the newspaper office near the high court office and also damaged machinery.
The fire in the building was brought under control after several hours of efforts by fire personnel. According to police, protests were held at several places here and in Cumbum, Theni, Kamuthi, Bodinayakanur, Gudalur, Dindigul, Tirunelveli, Virudhunagar and Tuticorin.