Mathura, Four passenger of a private bus were killed and eight others were injured when another vehicle hit the bus on the Yamuna expressway here on Wednesday morning.Police here said that the private bus from Katihar in Bihar was going to Delhi when it suddenly stopped near 105 milestones and a truck hit it from the rear.The incident occurred at around 0730 hours, killing four on the spot. Of the injured, condition of five was stated to be critical after they were admitted to different hospitals in Mathura.The deceased were identified as Mohammad Ramzani, Mohammad Samsher and Gopal Singh, all native of Katihar in Bihar while the truck driver Narendra Mishra of Prayagraj was also killed.