NSW man seriously injured after being bashed with tyre iron during home invasion

A man has been left with massive injuries after being attacked by four men with a baseball bat and a tyre iron at his home in NSW's Illawarra.

Police say they have been told the group went into the 30-year-old's Lake Illawarra home last night and attacked him in bed.

The man was taken to hospital after seeking help from a neighbour, and is in a serious condition with bleeding on the brain and multiple fractures to his face and vertebrae.

Police have called for any witnesses to the incident.