Emergency services attended a serious two vehicle crash on the A970 at Sandwick.
Police Scotland said officers were alerted to the crash at around 3pm.
Scottish Fire and Rescue also attended with two crews from Lerwick and one from Sandwick called to help.
Crews used cutting equipment to free trapped casualties.
The ambulance service also attended.
It is believed three people were taken to hospital with injuries that are not thought to be life-threatening.
The road was closed and diversions put in place.