Six persons were killed when their jeep collided with a truck while returning from Ujjain's Simhasta Kumbh Mela on Saturday.Nine others were injured in the accident that occurred near Kulhari village on the Agra-Mumbai National Highway. The victims hailed from Gorakhpur district of Uttar Pradesh and were on their way home from Ujjain. Kolaras Sub-Divisional Officer C.K. Arya told reporters that the injured were admitted in a hospital.