Update 7.26am: It is understood a 37-year-old man was arrested at 2am Wednesday, while a manhunt for two others continues.
Update 7.10am: Police and detectives are preparing a statement. No further details.
Update 8.45pm: "She put up a really good fight, they knocked her to the ground."
A witness to one of the incidents has told Fairfax she was driving on St George Avenue when she saw a black car travelling "very, very fast" hit the curb and come unstuck.
She pulled over about 30 metres away intending to offer assistance to the driver, she said, meantime another Good Samaritan - the 43-year-old woman driving a silver Toyota - pulled up behind the black car.
A third car, coloured white, then pulled up behind.
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"I saw the driver [of the black car] open the door, drag the woman out, take her behind the car and take her either to the front passenger seat or the back seat," the witness said.
"It looked like he was trying to bundle her inside. She was putting up a fight. She was screaming.
"Later on I realised on of the guys from the [white] car pulled up behind had gotten out, he started hitting her. They both started laying into her."
"She put up a really good fight, they knocked her to the ground."
The witness said the man abandoned the crashed car and departed in the injured woman's silver Toyota.
She said the white car made a U-turn before speeding down the road past the injured woman and herself.
When the witness went to the injured woman's aid, she said she saw a knife with a blade 8-10 inches long on the ground nearby.
She said the woman was in shock and told her that her legs had been run over.
The witness said she had since learnt that the men had obtained one of the cars in a carjacking at the Caltex service station in Vincentia.
Update 7pm: Police have called in the dog unit, which is en route, to assist with the manhunt.
Update 6.15pm: A woman injured in a carjacking at Vincentia has been taken to Shoalhaven Hospital in a stable condition.
The woman was standing behind the car when she was knocked to the ground and run over. She remained conscious throughout, with injuries confined to her pelvic area.
Update 5.55pm: Police from Shoalhaven Local Area Command are investigating reports of the theft of several cars, which may have been used by three offenders.
A police operation is now underway in the area, aimed at locating the cars and the offenders.
As at 5.55pm, the men are only described as being of Aboriginal/Torres Straight Islander appearance.
Police advise that members of the public are urged to report anything suspicious to triple zero and not to approach the men.
Earlier: A woman has been injured in a carjacking, which followed an armed robbery, at Vincentia on Tuesday evening.
NSW Ambulance paramedics were called to the aid of a 43-year-old woman on St George Avenue, shortly after 5pm.
Fairfax understands the woman was forced from her car. Initial reports indicate she was then struck by the car.
She suffered injuries to her pelvis and lower legs, and shock, and is en route to hospital.
The car continued onto Bayswood Avenue, where it has been dumped and set alight.
Fairfax understands the the culprit was involved in an armed robbery reported at a jewellery store on Owen Street at Huskisson five minutes earlier.
There, a female teenager suffered cuts to her legs.
Police are pursuing the offender, or offenders, and have been unable to provide further information as at 5.30pm.
More to come.
NOTE: An earlier report wrongly indicated that the woman hit by the car was aged 25. This has since been corrected to reflect her true age, 43.