Seven policemen and a Maoist prisoner were killed in a road accident in Bihar's Sitamarhi district on Saturday, police said.According to police officials, five policemen and one undertrial Maoist prisoner were also injured in the accident that occurred when the van they were in collided with a truck in Gaighat village, under Runnisaidpur police station on the Muzaffarpur-Sitamarhi road.The injured have been admitted in a private hospital."The accident happened when a police van carrying two undertrial Maoist prisoners and 12 policemen was hit by a speeding truck, which had lost control. Seven policemen and one undertrial Maoist prisoner were killed," a police official, Ashish Nandi, said.