Thieves have stolen thousands of litres of fuel from companies in southern Ontario, and the latest target is a bus company whose vehicles transport children to school.

Police say it's unclear if the cases are related.

In the latest heist, suspects cut the brakes of a school bus that was parked on top of a massive underground storage tank. They then pushed the bus out of the way, possibly using a truck, to access the tank's fuel.

Lynn Hohner was the driver of that bus, and told CTV Southwestern Ontario it had "been my baby since brand new." She had stern words for the people responsible for damaging the brakes.

"I think you've got a life out there, and I think you've got to work for it instead of taking it from others," she said.

Diesel prices have been coming down recently across Canada since a month-long shortage of fuel in the West, but they still average about $1.05 a litre in Southern Ontario.

Employees at the compound, which holds about 50 buses, believe the culprits stole tens of thousands of litres of fuel.

"We're thinking maybe 20,000 litres of diesel fuel was pumped out," said company spokesperson Brian Pawley.

But drivers still had enough fuel to make their daily runs.

"It's kind of exciting when you come to work and see all this action going on," said driver Michelle Dressel. "But you've still got to do the job and the kids have got to go to school."

Police are now collecting any evidence they can find and are examining tire tracks and tread patterns. Meanwhile, the company is thinking about increasing security.

"But you know, it's like anything else, you can do what you want but the people that do this type of thing are professionals," said Pawley.

The latest case follows at least two other fuel heists in the region. In mid-October, one fuel depot in Kitchener had 12,000 litres stolen, while thieves took 5,000 from another.

With a report by CTV Southwestern Ontario's Art Baumunk