Twenty-one people, most of them passengers on a KMB bus, were slightly injured when the double-decker collided with a refuse truck at a roundabout in Hang Hong Street, near Yiu On Estate in Ma On Shan. All the injured - 20 females aged between four and 60 and a 10-year-old boy - were allowed to leave after treatment at Prince of Wales Hospital. Police said the driver of the truck had lost control of his vehicle and rammed into the rear of the KMB bus.