The police vehicle was heading towards CJM court in Sopore – 48 kilometres north of Srinagar – from the Central Jail here when the blast happened near Time Pass restaurant in the area.
The prisoner has been identified as Noor Khan.
The injured policemen have been shifted to a nearby hospital for treatment.
The cause of the blast was not immediately known. However, sources said that an explosive device went off inside the car.
The deceased, Waheed Noor Khan is a Pakistani prisoner (militant) who was killed when the explosive went off in a police gypsy. Injured policeman have been shifted to Srinagar after suffering severe injuries.