Police have arrested a woman on suspicion of dangerous driving causing death and grievous bodily harm after two pedestrians were mowed down as they crossed a road in Sau Mau Ping on Friday morning.

A woman, 66, died after suffering head injuries when she was apparently struck by a vehicle on Lee On Road at around 8.40am.

Her grandson, 3, was taken to hospital with injuries to his face and limbs.

Officers said a female suspect, 51, was being held as part of their investigation into the incident.