The incident occurred late last night when a jeep, carrying passengers, rammed into the stationary van from behind near Jhapahan village under Ahiyapur police station area of the district.
Ahiyapur SHO Chitranjan Thakur said that four persons died on the spot while six others received serious injuries in the incident.
Those killed in the incident have been identified as Qamaruddin, Nisa Khatun, Md Anwar Ali and jeep driver Md Israil, Thakur said adding that all the passengers travelling in jeep had reached Muzaffarpur railway station from Mumbai yesterday and they were going to their village located under Aurai police station of the district.