Two young brothers and their grandfather who were the subject of an Amber Alert have been reunited with their family after a Toronto police constable spotted their vehicle on Lake Shore Boulevard early Thursday morning and decided to pull them over.

The boys, ages two and four, had last been seen with their 70-year-old grandfather in Newmarket on Wednesday afternoon.

Police previously said that their grandfather dropped his wife off at a plaza across from Southlake Regional Health Centre, near Davis Dr. and Lundy's Lane at around 1:30 p.m. Wednesday. He was supposed to go park the car, but instead drove away with the two boys in the vehicle.

An Amber Alert was then issued for the boys at around 3 a.m. amid increasing concern for their well-being.

“It really came down to the amount of time that was ticking and the level of concern hat we had for the children’s well-being because we knew that they had gone a period of time without eating, possibly not even a change of diapers and we just weren’t sure whether the grandfather was capable of taking care of the children appropriately,” Det. Gary Harvey told CP24 on Thursday morning.

Grandfather was confused but in good spirits: police

Police previously described the grandfather as a “vulnerable person” who likely didn’t know where he was going, as he was from Pickering and not familiar with York Region.

Harvey said that that given the period of time that had elapsed, police were concerned that the grandfather and the boys could be far from Toronto and at one point went so far as to notify the U.S. Border Service.

Luckily, they didn’t stray too far.

About 90 minutes after the Amber Alert was first issued, a Toronto police constable and his partner spotted the vehicle on Lake Shore Boulevard near Royal York Road and decided to pull it over.

One of those officers, Const. Richard Brown, told CP24 that the driver “was a little bit confused but in good spirits.”

He said that the two children were checked out by paramedics and then taken to a nearby McDonalds for a snack while their parents made their way to the scene.

“It was a very good team effort and the Amber Alert certainly did work,” Brown said.

“It is a great feeling,” his partner, Const. Joe Cicchirillo, added. “This is basically a 10 out of 10, this is as good as it gets.”

York police have said that the search for the boys and their grandfather drew in a significant amount of resources, including support from the Criminal Investigation Bureau, canine officers and the helicopter unit.