Theni, Feb 21 (PTI): Four persons were killed on the spot and eight injured when the jeep they were travelling in collided with a government bus at nearby Palanichettipatti early this morning. The occupants of the jeep were proceeding towards Cumbum from Karumathur after participating in the Sivarathri function when the mishap occurred, police said. They said two of the injured are in serious condition while others were treated as outpatients at a hospital. Poor visibility due to thick fog led to the collision officials said. In another accident, a father and his minor daughter riding a two wheeler were killed on the spot when their bike collided with a bus near Vaigai dam early this morning. The bus was proceeding towards Periyakulam from Andipatti.