Three men armed with baseball bats and an iron bar assaulted the victim at the White Sands Caravan Park in the early hours of Thursday morning in what police believe to be a domestic disturbance.

Police were called to the riverside caravan park at about 1.30am where they found the victim with serious head wounds.

He was transported to the Royal Adelaide Hospital with a fractured skull and a cut to his left arm.

The Murray Bridge Police Criminal Investigations Branch believe the victim knew his attackers and have called on members of the public to assist in the investigation.

The owners of the White Sands Caravan Park did not wish to comment, saying they wanted to put the incident behind them.

Murray Mallee Police spokesman senior sergeant Steve Scholefield said yesterday police were yet to make arrests in relation to the attack.

Meanwhile, detectives arrested a 41-year-old man in Murray Bridge on Thursday, suspected of stealing $10,000 in cash from a house in Warrnambool, Victoria.

The man appeared at an Adelaide Magistrates Court extradition hearing last week and was expected to appear in court in Warrnambool yesterday.

South Australia Police detectives, as part of Operation Dimension, have also arrested another 41-year-old man for a robbery at the Murray Bridge Post Office along with several other people suspected of involvement in a recent spate of armed robberies in Adelaide.

- Details: Anyone with information on the White Sands attack can contact Crime Stoppers on 1800 333 000.