Four people, one a four-year-old boy, were taken to hospital after a boat crash on Otago Harbour yesterday. 

Senior Sergeant Anthony Bond said a small boat crashed into a sandbar near Quarantine Island about 7.10pm on Sunday. 

The boat had six passengers and the cause of the crash was unknown, he said. 

A 38-year-old male was concussed and received a laceration to his forehead. 

The four-year-old boy received a bloody nose. 

A St John spokeswoman said two ambulances took four patients to Dunedin Hospital, all in a moderate condition. 

The boat was left on the sandbar for retrieval, Snr Sgt Bond said.