A wildcat bus strike spread across the capital today amid claims that drivers have intimidated others attempting to work.
Dublin Bus said staff involved in a third day of unofficial action had gone to bus depots throughout the city in a bid to extend the dispute.
Commuter routes across Dublin were being crippled by the action over timetable changes.
A spokeswoman for the firm said that, while there were no pickets, there was a presence which was “making itself felt outside our other depots”.
“We have had incidents already this morning where drivers who want to work and have gone in to work to take out their buses have been intimidated,” she said.
The row initially centred on Harristown near Dublin Airport after one driver was suspended for refusing to work the new staff rota.
It quickly spread to Clontarf, where drivers walked out in support, creating a public transport shutdown in the north of the city.
Dublin Bus said buses from Conynham Road and Summerhill depots – which include services to Ballyfermot and Clondalkin on the southside – have also been affected.
“We’ve had broken windows coming out of buses in Phibsborough and we’ve also had a female driver who was so intimidated that she had to return back to her garage manager,” added the spokeswoman.
“We really appeal to drivers to return to work.”