Lucknow: Four persons were killed and over three dozen seriously injured on Tuesday when a passenger bus rammed into a mini-truck in Uttar Pradesh's Bahraich town, police said. The accident took place around 4 a.m. on the National Highway 28C when the bus carrying passengers from Butwal in Nepal was headed to Delhi. The packed bus was overspeeding, according to an eye witness. A police official said that the bus was severely damaged in the collision. Eight of the injured persons were said to be in critical condition, the official added.