Livestock owners are being urged to make sure their animals cannot escape onto roads after two horses were killed and four people seriously injured in a "catastrophic collision" on the A3.

The two horses, named Fox and Lowri, had escaped from Surrey Grazing boarding stables in Oxshott and walked onto the southbound carriageway of the A3 where they were hit by four vehicles on December 16, 2015 at 3.40am.

One was a motorcyclist who was transporting blood and platelets to Frimley Park Hospital.

Four people involved in the crash suffered "life-changing injuries", according to Surrey Police officers.

The road was also closed for some six hours.

Sergeant Eddie Ryan said: “This was a catastrophic collision was has resulted in life-changing injuries for four people and led to the deaths of two horses.

“It also caused huge delays across the area for more than six hours while the road was closed.

“It is a stark reminder that if you own livestock, or allow livestock to graze on your land near a road that they must be kept in a secure area or there could be tragic consequences.”

Rosemary Gibson-Miller, 49, of Church Hill in Pyrford, was found guilty of allowing an animal to stray onto the highway at Redhill Magistrates' Court on January 11.

She was fined £500 and ordered to pay costs of £700.