Three teens are in custody and the Special Investigations Unit has been called after a vehicle being chased by police struck three pedestrians in Oshawaearly Sunday morning.

Police said they were called to the King Street West and Park Road area at approximately 2:45 a.m. after they received reports of a black truck driving erratically.

When officers attempted to stop the truck, it sped away. Police say the truck then hit three pedestrians in the King Street and Stevenson Road area.

The pedestrians – a 39-year-old man, a 28-year-old man, and a 32-year-old woman – were taken to Lakeridge Health Oshawa with serious injuries. One of them has since been transferred to St. Michael’s Hospital in critical condition.

The victims had just left the Out Lounge, which was hosting an event for Pride Week, and were standing on the grass when they were hit, according to the club’s security guard who witnessed the incident.

“I heard a loud screeching sound and I looked over and saw a truck going the wrong way on King Street,” Shantel Persaud told CTV Toronto of the crash. “The truck actually started skidding, it turned itself around, hit two people that weren’t even on the sidewalk.”

The truck then hit a tree, said Persaud. “People went flying.”

Police said the car's three occupants – two 13-year-olds and a 15-year-old – got out of the crashed vehicle and ran. They were taken into custody after a brief foot chase, according to Durham Regional Police Insp. Nick Lisi.

"The pursuit was very quick. It was instantaneous," Lisi told reporters Sunday morning.

Lisi said the three suspects from Whitby, Ont. weren't old enough to drive, and weren’t supposed to have the car, but couldn’t elaborate further.

“It’s very unfortunate, that’s for sure. They shouldn’t be driving,” he said.

Charges are pending against the suspects.

Ontario’s police watchdog is investigating the incident. The Special Investigation Unit is called whenever there has been a death, serious injury or allegations of sexual assault while interacting with police.

With files from CTV Toronto’s Naomi Parness