A car thief in Winnipeg sped off with a woman's vehicle while her young son was still inside, sitting in the back seat.

Police say the 40-year-old woman pulled up to a house on Park Place East, in the city's South Tuxedo neighbourhood, just after 5 p.m. on Wednesday.

She went to the house to pick up her daughter, leaving her son and car keys in the vehicle. While at the front door of the house, the woman turned to see a man jump into the car and speed away.

The woman ran after the vehicle then ran back to the house to call police.

The car was found abandoned soon afterwards, not far away in the area of the 700 block of Park Boulevard South.

The boy had already been found unharmed by a resident in the area, police said. A short time later, the mom and her son were reunited.

"It did just take moments for this individual to approach that vehicle, get inside and drive away — an incredibly traumatic incident for this particular parent," Const. Jason Michalyshen told reporters Thursday.

Police said a purse was stolen from the car by the suspect, who is described as about 20 years old with short, dark hair and dark clothing.

He had been seen as a passenger inside a red or burgundy SUV just before the woman's car was stolen, police said.

Anyone with information regarding the incident or suspect is asked to contact investigators at 204-986-2877 or Crime Stoppers at 204-786-TIPS (8477).

Michalyshen said the incident serves as a reminder to parents not to leave their children unattended in a vehicle.