KOLLAM: An explosive substance was hurled at the office of a TV channel in Kollam early Sunday morning, police said.According to police, CCTV footage from the area and the channel’s office showed two persons arriving on a two-wheeler, with one of them throwing a flaming bottle at the building.Police said two journalists were asleep inside the office when the incident occurred around 3 am and were unaware of it.The incident came to light later in the morning when a driver employed by the channel reached the spot and noticed burn marks on a step of the staircase along with broken pieces of a bottle, police said.He subsequently alerted the journalists, following which the police were informed.Police said statements of the journalists and the driver were being recorded, after which a case would be registered.The contents of the bottle will be ascertained after a forensic examination, police added.