The mishap took place near Dhalpur, about 35 Kms from here, when the vehicle dashed against Sambalpur-Puri Inter-City Express while trying to cross the railway track at an unmanned level crossing, police said.
Members of a family from Talabahala in neighbouring Angul district were proceeding to a temple in Dhenkanal when the mishap took place, killing five people, including the driver of the jeep, they said.
The four injured persons have been shifted to SCB Medical College and Hospital at Cuttack and their condition was stated to be critical, police said adding that the jeep was severely damaged and split into pieces under the impact of the collision.