The incident happened in the early hours on Thursday when four motorcycle-borne youths hurled two crude bombs packed in tiffin boxes, police said.
No one has been detained in this connection and police were examining various clues. Meanwhile, journalists protests in Chennai against the attack.
Journalists in the Puthiya Thalaimurai channel said nobody was injured in the incident and that no major damage to property was reported. They said the incident had been caught on CCTV camera.
The incident comes close on the heels of the channel removing a controversial show about 'Thaali' (Mangalsutra) on Sunday when a fringe outfit, Hindu Munnani, opposed it and staged a protest during which some equipment was damaged and a video journalist allegedly attacked.