Road blocks have been installed and VicRoads have advised that all lanes are closed westbound on the Western Highway at Aherns Road, with police directing traffic.

Two people have been assessed at the scene. 

One man, believed to be in his 40s has been airlifted to the Alfred Hospital in a serious condition with head and chest injuries.

A second person has been transported by road to Ballarat Base Hospital. Their injuries and condition are not yet known.

The location of the Beaufort crash.

An air ambulance is at the scene of the crash, preparing to take a man in his 40s.

Crews also attended the scene of a three-car collision at the corner of Rubicon and Skipton streets in Sebastopol about 1.15pm.

Part of Rubicon Street was blocked off.

It is believed one car crashed into three parked cars.

A white Holden Commodore is believed to have collided into the rear of a blue Toyota, plus two other cars.

The location of the Sebastopol crash.

An ambulance was on the scene. One man in his 60s was taken to Ballarat Base Hospital.

Emergency services were asking drivers to avoid the area if possible.