Tyres on about 50 heavy vehicles were damaged by a single screw sticking up from the road surface yesterday, delaying traffic for more than three hours. The incident involved buses, trucks and coaches on a section of Tuen Mun Road, near Yau Kom Tau, travelling in the direction of Tuen Mun. KMB confirmed a total of 58 tyres on 36 buses were damaged after running over the screw and hundreds of passengers had to be transferred to other buses. No one was injured. The Highways Department said inspectors had not spotted the protruding screw, and apologised. A KMB spokesman said: "About 40 bus trips were severely affected and the damaged buses all needed to be immediately repaired." The spokesman added: "If it is a case of … negligence of a third party, KMB will proceed with recovery action for its losses, including those incurred by the cancellation of the 40 aforesaid bus trips, against the responsible parties." One truck driver said repairing four of his damaged burst tyres would cost him at least HK$20,000. "My tyres were leaking air quickly. I thought only the two tyres on the left were burst, but it turns out it was all four," he said. Another driver said he could feel his tyres leaking air. Most of the affected vehicles immediately had their tyres replaced or were towed away. Chiang Chi-wai, chairman of the Lok Ma Chau-Hong Kong Freight Association, said the Highways Department should be responsible for compensating the affected drivers. "Although drivers or car owners could make claims from their insurance companies, they will have to pay an excess that ranges from HK$10,000 to HK$15,000," he said. "The damage was not caused by drivers and they should not have to pay that sum of money," he added. Traffic returned to normal near noon. The Highways Department fixed the problem by 10am and reopened the section of road. Pan-democrat lawmaker Gary Fan Kwok-wai, deputy chairman of the Legislative Council's transport panel, said the Highways Department should make detailed checks on the cause of the accident to avoid it happening again. The Highways Department apologised for the inconvenience caused. A spokesman said follow-up action had been carried out and a contractor would carry out further road inspections. "Inspections conducted by contractors and engineers found no abnormalities on the section of the road concerned, he said. "The cause of the accident is still under investigation."