A Kaitaia school bus driver has resigned over his frustration at the behaviour of the children he carries, with the final straw being an alleged assault by a teenager.

The man, who is in his late 60s and has requested to remain anonymous, said he was punched by a teenager when he could not pick his friend up because his bus was already closed and leaving the bus stop.

He said he has been in the job for eight years and endured verbal abuse, foul language and vandalism - but the assault was his limit.

He said the company told him there was nothing they could do and he believed the police would not be able to act either - so there was no other choice but to leave.