'Brazen' hammer attack leaves man with fractured skull, brain bleed

The alleged assault took place in a residential street of Warrawong, just metres from a local high school. (ABC Illawarra: Brooke Chandler)

A 44-year-old man victim suffered a fractured skull and bleeding on the brain after allegedly being attacked with a hammer south of Wollongong.

A teenage boy has been charged with stealing a car that was allegedly seen leaving the scene of the attack.

Police plan to speak to the victim and are urging anyone with information to come forward.

A man is in hospital with a fractured skull and bleeding on the brain after what NSW Police describe as a "fairly brazen daylight attack" involving a hammer.

The 44-year-old victim was allegedly assaulted by two people as he got out of a car they were in on Oxlade Street, Warrawong, in Wollongong's south, about 2pm on Friday, June 5.

Lake Illawarra Police District Chief Inspector Dave Cockram said the offenders drove from the scene in a white Suzuki Vitara before officers and paramedics arrived.

"The extent of the injuries that the fellow suffered is pretty concerning," he said.

"We understand that a number of items were used during the assault, potentially some tools."

Police believe the victim may have been returning home when he was alledley assaulted with a hammer. (ABC Illawarra: Brooke Chandler)

The victim was flown to a Sydney hospital, where he remains in a serious, but stable condition.

Due to the extent of his injuries, he has not yet been able to speak with police.

About eight hours after the alleged assault, police recovered the Suzuki Vitara following a chase in the Sydney suburb of South Granville, about 90 kilometres north-west of Warrawong.

Two teenage boys were arrested nearby and a third was questioned by police.

A 15-year-old boy has been charged with driving and stealing offences and will face a children's court in July.

Police allege the white Suzuki Vitara was stolen during a break and enter at a home on Alison Street in Seven Hills sometime between 11:30pm on Thursday, June 4 and 5:30am on Friday, June 5.

Dave Cockram says it is unclear what instigated the alleged attack. (ABC Illawarra: Brooke Chandler)

Chief Inspector Cochram said it was not yet clear whether the teenagers were involved in the attack at Warrawong, but finding the remaining three people was "very important".

"We can't say for sure if that is what has occurred, but that is certainly a line of inquiry we are interested in," he said.

"A pretty significant thing that has gone on and we'll be working hard to bring those to justice."