A drive-by shooting on a Mississauga highway that left a man dead and two others critically injured appears to have been targeted, Peel police say.

The shooting happened on a northbound Highway 410 off-ramp at Derry Road. Police, paramedics and firefighters were called to the scene at 9:48 p.m. on Tuesday.

A man without vital signs was pronounced dead at the scene. A man and a woman were critically injured and were listed in life-threatening condition in a trauma centre on Wednesday. All three were in a vehicle when shot.

Const. Danny Marttini, spokesperson for Peel Regional Police, said on Wednesday that homicide detectives are now in charge of the investigation.

"It's hard to say [if] it's targeted or not, but just by the style of it and from different incidents I have dealt with in the past, I would say it has that marking of being targeted. It's not a random shooting," Marttini told reporters.

Marttini said police were told that the vehicle the victims were in had just exited the northbound lanes of Highway 410 at Derry Road and was about to make a turn onto Derry Road to go westbound when another vehicle came up beside them. Several shots were fired into the passenger side.

Police say there were a number of other cars on the highway at the time of the shooting and that means there is a good chance that there were witnesses. (CBC)

Then the vehicle from which the gunfire came sped away, she said.

There were a number of other cars on the highway at the time and that means there is a good chance there were witnesses, Marttini added.

Police have not released the name of the man who died nor his age.

No arrests have been made. Police are still looking for suspects but have not released any descriptions. Officers are notifying next of kin.

Police have reopened a stretch of Derry Road, from Kennedy to Tomken Roads, and two Highway 410 off-ramps to Derry Road, northbound and southbound, after investigating for hours.

Attack not connected to fatal shooting at condo

Marttini said the Highway 410 shooting is not connected to a fatal shooting outside a Mississauga condo on Webb Drive, near Burnhamthorpe Road and Confederation Parkway, shortly before midnight on Tuesday. A male driver was shot in a vehicle.

A car with several bullet holes is seen outside a condo building in Mississauga. One man was pronounced dead at the scene. Police say the attack is not connected to a shooting on Highway 410. (Jeremy Cohn/CBC)

Witnesses have told investigators that a man approached the victim on foot, fired several shots into the vehicle and then fled across the street.

The driver, the sole occupant of his vehicle, was pronounced dead at the scene.

The attacker may have left in a vehicle after fleeing on foot onto Burnhamthorpe, Marttini said.

Anyone who was driving through the area and may have dashboard camera video is urged to contact police.