The compound wall of the theatre was damaged. None were present in the theatre when the incident occurred, they said.
Members of 'Puratchi Puligal' (Revolutionary Tigers) surrendered before police and were later arrested, they said.
The activists claimed that the film contained derogatory dialogues about Dalits.
Police said they had hurled the bombs just to gain publicity for their outfit.
Recently, some Dalit outfits, including Athi Tamizhar Katchi, had staged a demonstration in front of the theatre, but were arrested and later released with a warning.
Police said strict action would be taken against those who indulged in such actions.