A 19-year-old man is in a stable condition under police guard at Royal Darwin Hospital after a two-car crash in Howard Springs early this morning.

Key points: Allegedly stolen sedan crashed into four-wheel drive in early hours of Sunday morning

Allegedly stolen sedan crashed into four-wheel drive in early hours of Sunday morning Five hospitalised, including 19-year-old who fled the scene and was later captured

Five hospitalised, including 19-year-old who fled the scene and was later captured Stuart Highway has fully reopened to traffic

Four other people are in hospital, two of them in a critical condition, after the high-speed crash between a sedan and a four-wheel drive on the Stuart Highway around 3:00am.

Police said a teenager fled the scene after the driver of the sedan ran a red light in the allegedly stolen car at 185 kilometres per hour.

Three passengers from the sedan were taken to hospital, along with the driver of the four-wheel drive, whose condition is now critical.

The crash, which closed the Stuart Highway at Howard Springs Road, appears to be the dramatic end to what police believe was a crime spree spanning several hours throughout Darwin, including an armed robbery and a carjacking.

Sedan crash victims robbed pizza delivery man: Police

Police allege that around 8:00pm yesterday, a stolen white Mitsubishi Mirage hatchback rear-ended a white Holden Commodore, at the intersection on Mataram and Winnellie Roads in Winnellie.

"While the Commodore was stopped, three youths from the stolen vehicle forced the three occupants from the car and headed toward the city in both vehicles," Commander Michael Murphy said.

How the crime spree unfolded Sunday 8:00pm: In a stolen white hatchback, two young men and a female teen rear-end a white Commodore, which they then carjack at the intersection of Mataram and Winnellie Roads, Winnellie

Sunday 8:00pm: In a stolen white hatchback, two young men and a female teen rear-end a white Commodore, which they then carjack at the intersection of Mataram and Winnellie Roads, Winnellie Sunday midnight: The group allegedly rob a pizza delivery man in Fannie Bay

Sunday midnight: The group allegedly rob a pizza delivery man in Fannie Bay Monday 3:00am: The sedan, travelling at more than 185 kilometres an hour, crashes into a 4WD in Howard Springs

Monday 3:00am: The sedan, travelling at more than 185 kilometres an hour, crashes into a 4WD in Howard Springs Monday 1:00pm: Police announce they have captured a teen who fled the scene on foot

The victims reported that one of the youths may have had a firearm in his belt.

Police then located the two stolen vehicles being driven on Temple Terrace in Palmerston.

"A short pursuit commenced, with the stolen vehicles separating," Commander Murphy said.

"The pursuit was terminated when the Commodore was driven onto the wrong side of the road."

Earlier, police confirmed they initially tried to stop the driver, but Deputy Police Commissioner Mark Payne said it was decided not to pursue the car due to issues of public safety.

"We took an early decision not to put these young people under pressure because there was a clear indication that had we done so that their driving behaviours would have become more erratic than they actually were at that time," he said.

Shortly after midnight police then received a report of an armed hold-up in Fannie Bay, where a pizza delivery man on a scooter was robbed of the cash he was carrying.

"One of his assailants had a firearm and they fled in the stolen Commodore," Commander Murphy said.

Police then found a shotgun which met the description of the weapon used in the robbery at the scene of the crash.

It was also confirmed that the vehicle was not under pursuit at the time of the crash, and described the crash scene as horrendous.

Police Superintendent Bob Rennie said Major Crash and crime investigators were now examining the wreckage.

All roads affected by the two car crash in Howard Springs this morning are now open.

The white Mitsubishi Mirage remains outstanding.