Schools across Quebec have been forced to cancel bus service after the government pulled all of the roughly 1,200 Lion electric buses in the province off the roads.

The provincial government said it took the precautionary measure after a Lion electric school bus caught fire in Montreal earlier this week. Several children and a driver were inside the bus when it caught fire, but no one was injured.

In a joint statement Thursday evening, Education Minister Sonia LeBel and Transport Minister Jonatan Julien said a "defect" may have caused Tuesday's fire. 

"The preventive vehicle inspection operation will take place all weekend to allow normal school transportation to resume as quickly as possible," they said. "If adjustments to the vehicles are necessary, alternatives will be offered to parents for transporting their children to school next week."

First Student, the parent company of Transco, which owns the bus that caught fire, said in a statement Friday that it had identified a "wiring issue within the manufacturer's system" and flagged it to Lion and Transport Canada. It said it had removed "all affected buses" from service pending "a longer-term solution from Lion."

Lion said it is working with school bus operators and Transport Canada to confirm the safety of its buses and restore bus service. A spokesperson for the Montreal fire department said Tuesday's fire was unrelated to the bus's battery. 

This is not the first time a Lion bus has gone up in flames. Last November, a bus caught fire in Ascot Corner, in Quebec's Eastern Townships region. A second bus caught fire in Huntsville, Ont., in January. Nobody was injured in either case, and the batteries were not involved. 

In a statement Friday, a Transport Canada spokesperson said the root cause of the fires has not yet been determined "due to the extent of the fire damage."

Andrew Jones, a Montreal-area school bus operator, said he got word at 11:30 p.m. on Thursday that the government had grounded all Lion buses. He said he had to wake up his office staff that night and make plans for getting students to school the next morning. 

Jones's fleet includes eight Lion buses, which he was able to replace with spare diesel or gas buses on Friday, so service to students was unaffected. But he said his own mechanics have had to inspect the buses, using guidance from Lion. 

"It's all on our dime," he said. "The unfortunate thing is that we did have other vehicles today … that we needed to inspect. That's been all put on the back burner to focus on these vehicles."

As of noon Friday, Jones said his mechanics had already gone over two buses, and found "nothing that would be alarming." He said Lion instructed operators to inspect the connector cables for the heating system, and his mechanics have reinforced the cable harnesses to better protect them. 

Chantale Dugas, president of the Quebec federation of bus operators, said the incident "should not be taken lightly," but pulling the buses off the road presents a challenge to operators. 

"A service outage like this means the families and the carriers will have to bear the costs," she said. "So there is collateral damage."

In response to the government's decision, some school service centres chose to cancel bus routes on Friday, while others cancelled the school day entirely.

The Centre de services scolaire de Montréal warned that school bus transportation would be "disrupted for an indefinite period," and asked parents to find alternative solutions if necessary. The English Montreal School Board had to cancel more than 70 routes usually served by Lion buses, while the Centre de services scolaire des Grandes-Seigneuries on Montreal's South Shore cancelled more than 50 routes.

At least two school service centres in central Quebec cancelled classes outright due to the bus service interruption. 

Meanwhile, the government of Prince Edward Island says it's "closely monitoring the situation" in Quebec and will conduct additional maintenance checks of the 107 Lion buses in that province. 

"The electric buses in P.E.I. have not experienced the same issues as in Quebec," a spokesperson for the Transportation Department said in an email. "However, should any actions be required to safeguard the well-being of students, we will take appropriate and timely action."

Lion has had major financial problems in recent months. After seeking protection from its creditors in December, the struggling manufacturer was acquired by a group of Quebec investors in May with a plan to focus exclusively on electric school buses assembled and sold in the province.

Montreal resident Stefano Rover said he saw the Lion bus engulfed in flames on Tuesday while he was out for a bike ride. He said the orange flames were so bright that it was "almost surreal."

When he returned two hours later, he said he saw the charred bus being removed from the scene on a flatbed.

– Mathieu Paquette and Maura Forrest, The Canadian Press

With files from Fatima Raza in Toronto.