Students evacuated from bus that caught fire in Sydney's south

More than 20 students have escaped injury after the bus they were on caught fire in Sydney's south.

The bus was in front of Aquinas Catholic College and Holy Family Catholic Primary on Anzac Road in Bangor when the fire started just after 3pm on Wednesday.

No students were injured as the driver escorted them off the bus when he smelt smoke.

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Holy Family Catholic Primary said there had been an "incident" with a bus.

"All children are safe and have been removed from the area," the school said in a statement.

A witness told 9News it escalated really quickly.

"You've got all the parents picking up the small ones, all the biggies trying to get on to the buses and of course you know you see this smoke and then all of a sudden you see all these flames shooting out," the witness said.

"The glass is fracturing and popping and you're thinking is it going to explode?"

A spokesperson from bus operator U-GO Mobility said the bus was route S702 and a replacement bus was arranged for some students.

"Initial reports indicate the fire may have been electric," the spokesperson said.

"Our maintenance team are on site undertaking initial investigations.

"We are working with the TMC (Transport Management Centre) and are awaiting further advice on the removal of the bus."

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