NSW probe into crash involving police

Seven people have been taken to hospital after a car that police were chasing crashed into another car at an intersection in NSW's Hunter region.

Police have launched a critical incident investigation after the head-on collision at speed in East Maitland at about 12.45am (AEDT) on Monday that left one person in a critical condition and three others seriously injured.

A Ford Fairmont station wagon, which officers had tried to stop, attempted to enter an intersection when it collided with a Holden Commodore sedan, police said.

Emergency services were called and freed people trapped in the wreckage, with one rescue taking about an hour and a half.

Two men and two women in the Ford were taken to John Hunter Hospital with various injuries while a man and a woman in the Holden were taken to Maitland Hospital.

A police officer was also taken to Maitland Hospital for observation but police were unable to tell AAP why.

Police said the Critical Incident Team would investigate the incident, including the actions of police, and their report would be reviewed by an independent officer.