The boy was run over yesterday morning by a four-wheel-drive  on a challenging track known as Clymies Track, about  five kilometres north of Trial Harbour, on the West Coast.

The woman was killed in a three-car pile-up on the Bass Highway at Rocky Cape yesterday afternoon.

The boy, from the Huon, was part of a group from the South of the state touring the area in four-wheel drive vehicles.

He was run over by a vehicle conducting a low-speed manoeuvre. 

The boy died before emergency services arrived. 

Police, Ambulance Tasmania and a rescue helicopter attended the accident.

The woman was a rear passenger in a blue Toyota Echo involved in a three-car collision on the Bass Highway at 4.30pm yesterday. 

Police, State Emergency Services and ambulance personnel attended the scene.

Emergency services blocked off  the Bass Highway and diverted traffic through Montumana Road.

Police stayed at the scene until late into the night.

By 9.30pm police still had not released the name and age of the woman who died, nor any information on  injuries sustained by others involved in the crash.