For the third time in ten days, a Dublin Bus service was forced to stop serving part of it's route.
The number 27 avoided the Brookfield and Jobstown areas after the latest outburst of anti-social behaviour.
The service has been plagued by problems in recent months with both buses and drivers coming under attack.
Sean Yeates from the National Bus and Rail Union says they may have to pull buses;
"Health and Safety has to take priority for the customers and the drivers and the union are going to have to sit down in the next couple of weeks and decide are we going to continue with this or are we going to have a day where we say enough is enough."
He says stones have been thrown at buses and there have been racial assaults, physical assaults and passenger fights on board.
Drivers had threatened not to operate the service on the day of the General Election in protest at the persistent problems but the action was averted.