Ontario's ombudsman is looking into whether a systemic investigation is warranted into a school bus shortage that's left thousands of Toronto students stranded without a way to get to school on time.

"Over the past few days, we have heard media reports as well as complaints from frustrated parents who waited for their children to be picked up or dropped off, only to have no bus show up," Paul Dubé said in a release Friday. Since September 1, 2015 the ombudsman's mandate has included overseeing all Ontario school boards.

Ontario's ombudsman is looking into whether a systemic investigation is warranted into a school bus shortage. (CBC)

"Among other things, our staff will look into what happened, what plans the school boards had in place, and what was done to inform parents," Dubé said, adding that the assessment will be done as quickly as possible.

At a news conference about all-day kindergarten Friday, Ontario's education minister Mitzie Hunter told reporters she expects Toronto's school boards to work with bus companies to solve the shortage. The province provides funding for the transportation, but it's up to school boards to figure out the co-ordination of buses, she said.

"We're meeting the demands that are being asked of us," Hunter said. "Since 2013 we've provided a 40 per cent increase of funding to the school boards."

Ontario education minister Mitzie Hunter says that since 2013 the province has provided a 40 per cent increase of funding to school boards. The Toronto District School Board (TDSB) is pointing the finger at third-party companies, saying they haven't been transparent about a lack of drivers.

The affected routes were contracted out to three different companies: Attridge Transportation, Wheelchair Accessible Transit and Sharp Bus Lines. The companies bid for the routes, which the school boards say they assumed would be covered. All three declined to comment to CBC News on how they're trying to fix the situation.

The TDSB and the Toronto Catholic District School Board say they have been on conference calls with the three companies to try to cover the routes.

Hunter says the shortage is a serious issue.

"I'm concerned," said the education minister. "This is something I'm monitoring very, very closely."

An ombudsman's investigation could see Dubé make recommendations to solve the problem as well as to improve transportation services for the future.