Auckland's Mayor is inviting Police to turn up unannounced on buses, to discourage violence and anti-social behaviour

Figures released exclusively to Newstalk ZB show emergency services are being called to more than nine incidents a week on buses, many of them violent.

There are more than 83 security incidents a week on trains -- an increasing number of them violent or disorderly.

Wayne Brown says the council is funding protective screens for bus drivers, but it can't guarantee protection to every passenger.

He says they can't afford to have a Police officer on every bus, but they have agreed to increase patrols at transport hubs and occasionally get on a bus.

Brown says he's told them they can get on the bus for free at any time, because he wants them to be seen out about about on buses.