6.35pm: THE Snowy Hydro SouthCare (SHSC) rescue helicopter is preparing to load patients after a serious crash near Hay on Friday afternoon. 

It is unclear which patients will be airlifted, but information from SHSC indicated a "multi-trauma patient retrieval" was under way. 

3.20pm: A TEENAGER has been freed after she was trapped for about two hours in serious crash near Hay. 

Seven people have been assessed by paramedics - four are listed as serious. 

A number of children were inside a mini bus which was involved in an accident with a truck on the Sturt Highway, 15km west of Hay. 

A spokeswoman for the NSW Ambulance Service has confirmed seven patients have been assessed by paramedics and transported to hospital. 

The spokeswoman said a 16-year-old girl sustained a suspected fracture to her leg and was trapped in one of the vehicles for two hours. 

She has since been taken to Hay Hospital. 

Earlier, a one-year-old girl was rushed to Hay Hospital with a serious head injury. 

A 12-year-old male suffered a fractured jaw, while a two-year-old boy was treated for a bump to the head.

The spokeswoman said four ambulances were required to transport the patients to hospital.

Crime scene investigators are heading to the accident and the highway is expected to remain closed for most of the afternoon. 

2.45pm: THE Snowy Hydro SouthCare rescue helicopter has been tasked to the accident between a mini bus and truck west of Hay. 

A spokeswoman for Snowy Hydro Southcare said the helicopter was dispatched from its Canberra base about 20 minutes ago and the trip would take about an hour. 

It is understood it will land at Hay Hospital.  

2.30pm: EMERGENCY services remain at the scene of an accident between a mini bus and truck west of Hay.

The Sturt Highway is expected to remain closed for some time due to the complex nature of the clean up and salvage operation.   

1.40pm: A ONE-YEAR-OLD has been rushed to hospital in a serious condition after a mini bus and truck collided west of Hay on Friday afternoon. 

A spokesman for the NSW Ambulance Service said the toddler - whose gender is unknown - had suffered a large head wound and was being rushed to Hay Hospital. 

The child's mother is with them. 

Two doctors and two nurses are now being tasked to Hay in a fixed wing medical aircraft. 

Further reports suggest nine people, believed to be children, are being assessed by paramedics. 

The truck driver has escaped unscathed and is being conveyed to Hay Hospital for mandatory blood and urine tests.

The accident occurred shortly before 1pm and has closed the Sturt Highway in both directions. 

Light vehicles are being diverted in both directions via the Maude Road.

Heavy vehicles are advised to use Cobb Highway between Hay and Pretty Pine, Moulamein-Dawhilly Road to Moulamein, then north via Moulamein Road to rejoin the Sturt Highway.

Multiple ambulances are on the scene, along with members of the Hay SES, Fire and Rescue NSW and Rural Fire Service (RFS) crews.

1.10pm: EMERGENCY services are responding to a serious  accident involving a semi-trailer and car west of Hay.

The crash has closed the Sturt Highway in both directions 15km west of the town.

Motorists are advised to avoid the area.

The NSW Transport Management Centre says there is no diversion available at this time so motorists are advised to delay any travel on the Sturt Highway between Hay and Balranald.

More to come.