Six people have been killed and at least 42 others injured in a collision involving a bus and a truck in Central Java's Batang district on Saturday night (16/07), authorities said. National Disaster Mitigation Agency (BNPB) spokesman Sutopo Purwo Nugroho said the accident occurred on the Alas Roban Outer Ring Road at 7 p.m. when the Kramat Djati passenger bus collided with a truck which was making a u-turn. The bus was traveling at a high speed in the right lane to overtake vehicles, preventing it from avoiding the crash, Sutopo said. "Six people died at the scene, 42 others were injured and eight managed to survive. The killed and injured victims were rushed to Kendal Hospital," Sutopo told Detik.com on Sunday morning. Separately, Batang Police chief Adj. Sr. Comr. Joko Setiono said police will start investigations on Sunday morning by questioning the bus driver who has been detained. "We will dig deeper into the accident today ... we detained the bus driver at around 3 a.m.," Joko said, adding that truck driver is still receiving treatment at the hospital. Police ruled out naming the cause of the deathly traffic accident. "We are still in the investigation. We will tell you when it's done," said Joko. The accident triggered traffic mayhem on the Alas Roban Outer Ring Road throughout the night. Police and local agencies finished evacuations on Sunday before dawn.