One Dead After Carjacking, Stabbing And Crash

A person has been stabbed and another is dead after a car crash and carjacking in a crime spree through Sydney's south.

Police have rushed to the scene in Rockdale, after witnesses said a man crashed his car and then stole another vehicle, reportedly stabbing another man in the process.

The driver, who later died from self-inflicted wounds, was a 24-year-old man from Greenacre, was known to police. Authorities said the incident may be mental health-related.

Authorities later detailed a multi-suburb crime spree, alleging the driver refused to stop for police, then rammed their vehicle, stole a supermarket truck, crashed, stole another car, stabbed a man, then later died from self-inflicted wounds.

Footage from the scene, sent to 10 daily, shows a man ordering a driver out of a taxi, before jumping behind the wheel and speeding away as pedestrians watch on and record the encounter on their phones.

The man had stabbed another person before stealing that car.

Police in the nearby suburb of Arncliffe have surrounded a white sheet laid on the roadway, covering what is believed to be the body of the driver, nearby where the stolen taxi has been parked.

Emergency services responded to the area on West Botany Street, in a busy area near a supermarket and gym, after 3pm on Friday.

Officers are at multiple scenes around the area, at Rockdale as well as nearby Arncliffe and Yagoona.

A witness told 10 News First that "a good size" knife had been used in the stabbing. The victim is said to be in a serious but stable condition, and undergoing surgery in hospital.

"The incident began when police attempted to stop the driver of a 4WD, not displaying number plates, on the Hume Highway at Bass Hill shortly before 3pm," police said in a statement.

"The 4WD rammed the police vehicle and drove east towards Chullora, where he dumped the 4WD and stole a small supermarket delivery truck from Waterloo Road."

The incident continued through several collisions with other vehicles, before the man -- by that time, driving the stolen taxi -- got out of his vehicle at Forest Road, Arncliffe.

"He then produced a knife and commenced to inflict wounds upon himself in the presence of police," NSW Police said.

"Police rendered first aid; however, the man died at the scene."

A brief will be prepared for the coroner, and a police critical incident team will investigate the circumstances leading to the death.

A worker at the nearby Exodus Youth Worx youth centre told 10 Daily they witnessed a person get out of one of the cars and stab another person.

The worker said a truck and a number of cars were involved in the incident, with employees of the centre assisting up to five people who were involved in a crash.