Shimla, Aug. 21 -- Four labourers were killed and six others were injured after two trucks collided head-on inside the Dawada Tunnel on the Kiratpur-Manali highway on Thursday morning, police said. The deceased have been identified as Shakeel (20) from Bijnor, UP, Vishal (20) from Firozabad, UP, Meghnath Sharma (30) from Bihar, and Ravi Kumar (22) from Firozabad, UP. Police said all the victims were labourers from other states and were travelling to Kullu alongside a consignment of glass loaded in the truck. Police said that the exact cause of the accident is yet to be ascertained, however, preliminary investigations blamed speed and overtaking in the tunnel. According to the police, the accident occurred at around 6.30am inside Tunnel No. 12 near Hanogi Temple, approximately 30km from the Mandi district headquarters when a truck bearing a Punjab registration number was travelling from Mandi towards Kullu with nine people on board. Another truck, with a Himachal Pradesh registration number, was coming from the direction of Kullu towards Mandi. The driver and conductor of the truck were injured in the incident and are undergoing treatment at Nerchowk Medical College. They have been identified as Bhagirath and Mukesh Kumar, both 40, and residents of the Balh Valley in Mandi district. Police said that the impact of the accident was reportedly severe, leaving several people trapped or injured, the police said. Soon after receiving information, a police team reached the spot and began an investigation. Traffic on the Mandi-Kullu Highway was disrupted for some time following the accident. Mandi SP Vinod Kumar confirmed the death of four people and injuries to six others. He said that a case has been registered at Aut Police Station under Sections 281, 126A, and 106 of the Bharatiya Nyaya Sanhita (BNS), and an investigation into the cause of the accident has commenced. Further action will be taken based on the findings of the investigation....